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- Film Formation and Analysis
- Organic and Polymer Films
- Infrared and Optoelectronic Films
- Semiconducting Films
- Film Formation and Analysis
- Optical Films
- Organic and Polymer Films
- Film Formation and Analysis
- Semiconducting Films
- Film Formation and Analysis
- Infrared and Optoelectronic Films
- Film Formation and Analysis
- Superlattice Films
- Film Formation and Analysis
- Infrared and Optoelectronic Films
- Film Formation and Analysis
- Surface and Interface
- Film Formation and Analysis
- Semiconducting Films
- Film Formation and Analysis
- Surface and Interface
- Semiconducting Films
- Surface and Interface
- Organic and Polymer Films
- Ferroelectric and Dielectric Films
- Films for Magnetic and Optical Recording
- Semiconducting Films
- Optical Films
- Superlattice Films
- Superconducting Films
- Ferroelectric and Dielectric Films
- Infrared and Optoelectronic Films
- Film Formation and Analysis
- Semiconducting Films
- Organic and Polymer Films
- Infrared and Optoelectronic Films
- Film Formation and Analysis
- Ferroelectric and Dielectric Films
- Films for Magnetic and Optical Recording
- Infrared and Optoelectronic Films
- Semiconducting Films
- Infrared and Optoelectronic Films
- Film Formation and Analysis
- Films for Magnetic and Optical Recording
- Ferroelectric and Dielectric Films
- Surface and Interface
- Infrared and Optoelectronic Films
- Organic and Polymer Films
- Superlattice Films
- Organic and Polymer Films
- Film Formation and Analysis
- Optical Films
- Films for Magnetic and Optical Recording
- Surface and Interface
- Superlattice Films
- Semiconducting Films
- Infrared and Optoelectronic Films
- Superlattice Films
- Films for Magnetic and Optical Recording
- Optical Films
- Ferroelectric and Dielectric Films
- Film Formation and Analysis
- Superlattice Films
- Ferroelectric and Dielectric Films
- Superlattice Films
- Optical Films
- Organic and Polymer Films
- Film Formation and Analysis
- Superlattice Films
- Film Formation and Analysis
- Superconducting Films
- Ferroelectric and Dielectric Films
- Superconducting Films
- Optical Films
- Semiconducting Films
- Film Formation and Analysis
- Surface and Interface
- Film Formation and Analysis
- Surface and Interface
- Films for Magnetic and Optical Recording
- Surface and Interface
- Optical Films
- Surface and Interface
- Organic and Polymer Films
- Film Formation and Analysis
- Superlattice Films
- Films for Magnetic and Optical Recording
- Film Formation and Analysis
- Superlattice Films
- Ferroelectric and Dielectric Films
- Organic and Polymer Films
- Superconducting Films
- Semiconducting Films
- Ferroelectric and Dielectric Films
- Film Formation and Analysis
- Surface and Interface
- Infrared and Optoelectronic Films
- Ferroelectric and Dielectric Films
- Superconducting Films
- Superlattice Films
- Organic and Polymer Films
- Surface and Interface
- Film Formation and Analysis
- Surface and Interface
- Optical Films
- Organic and Polymer Films
- Film Formation and Analysis
- Semiconducting Films
- Film Formation and Analysis
- Superconducting Films
- Films for Magnetic and Optical Recording
- Optical Films
- Organic and Polymer Films
- Film Formation and Analysis
- Ferroelectric and Dielectric Films
- Film Formation and Analysis
- Semiconducting Films
- Superconducting Films
- Superlattice Films
- Optical Films
- Films for Magnetic and Optical Recording
- Film Formation and Analysis
- Films for Magnetic and Optical Recording
- Film Formation and Analysis
- Ferroelectric and Dielectric Films
- Film Formation and Analysis
- Films for Magnetic and Optical Recording
- Infrared and Optoelectronic Films
- Superconducting Films
- Infrared and Optoelectronic Films
- Surface and Interface
- Optical Films
- Film Formation and Analysis
- Semiconducting Films
- Superconducting Films
- Ferroelectric and Dielectric Films
- Infrared and Optoelectronic Films
- Superconducting Films
- Film Formation and Analysis
Film Formation and Analysis
Large-scale production of a broadband antireflection coating on ophthalmic lenses with ion-assisted deposition
F. Andreani,
S. Luridiana,
Shuzheng Mao
Show abstract
Antireflecting coatings are widely used in ophthalmic fields because they increase transmission and cosmetic properties of spectacle lenses. Adhesion and hardness are very important to ensure time durability of the coating. We improved these properties on plastic (CR39) lenses using IAD technique on large-scale production plant.
Organic and Polymer Films
Study of PEO on LTI carbon surfaces by ellipsometry and tribometry
Jinyu Wang,
Eric Stroup,
Xing Fa Wang,
et al.
Show abstract
Proteins absorb to almost all surfaces during the first few minutes of exposure. Surfaces that show minimal protein absorption are important in many biomedical applications. Moreover, patient discomfort due to poor lubricating action between tissue and various medical devices, especially contact lenses, is a serious medical problem. An effective polymer for protein- resistant surfaces and improved lubrication properties appears to be polyethylene oxide (PEO). Here we report a study of PEO films on low temperature isotropic (LTI) carbon surfaces, including preparation using a photochemical reaction, characterization of the thickness of the PEO layer by ellipsometry and measurement of coefficient of friction with a custom built tribometer.
Infrared and Optoelectronic Films
Photosensitivity of selenium-bismuth films with varigap structure
Anatolyi I. Popov,
N. Mikhalev,
A. Karalyunts,
et al.
Show abstract
The results of creating and investigating the electrophotographic layers on the basis of selenium-bismuth system with variable bismuth concentration along the thickness of the film are given. The samples for the investigations were obtained by means of thermal coevaporation of components on the oxidized aluminum substrate. Investigation of molecular and electron structure and those of electrophotographic properties of varigap films on the basis of Se-Bi showed the possibility of effective control of both spectral dependence and of absolute values of electrophotographic sensitivity of the films.
Semiconducting Films
Condensation mechanisms and properties of rf-sputtered a-Si:H
Valerie A. Ligachov,
V. A. Filikov,
V. N. Gordeev
Show abstract
The article is devoted to the influence of the technological parameters on the electrical and optical properties of a-Si:H analysis on the basis of a recently developed approach. It is shown that the region of critical values of deposition parameters Ts and Ph exists. In the vicinity of this region the alteration condensation mechanism of different SiHm (m equals 0,1,2,3) complexes is observed. The critical values separate the preparation conditions of two different types of a-Si:H material and correspond to non-equilibrium 'phase-transition.' The origin of 'pseudo doping effect' is discussed.
Film Formation and Analysis
Studies of correlation of molecular structure under preparation conditions for noncrystalline selenium thin films with aid of computer simulation
Anatolyi I. Popov,
Natalja V. Vasiljeva
Show abstract
We investigate short range and medium range order (MRO) in arrangement of atoms in non- crystalline semiconductors. It is shown that dependence of properties of non-crystalline semiconductors on their pre-hystoric period is determined by modifications in MRO in atoms arrangement. With the help of experimental research of non-crystalline selenium and computer simulation it was shown that as a quantitative criterium for the modifications of MRO of the material it is recommended to use energy characteristics: the total potential energy of the system and its various components.
Optical Films
Materials for optimal multilayer coating
Sergey V. Grebenshikov
Show abstract
Some corollaries of the necessary conditions for optimal multilayer optical coating synthesis are presented. Multilayer coatings, consisting of natural absorbing materials with complex permittivities (epsilon) equals (epsilon) ' + i (DOT) (epsilon) '' are considered. The principle of optimal materials choice and order of alternation is formulated. It is shown that the optimal coating is multimaterial.
Organic and Polymer Films
Optical transition characteristic energies of amorphous and polycrystalline tin oxide films
M. Rasat Muhamad,
W. H. A. Majid,
Z. Ariffin
Show abstract
Thin films of tin oxide were prepared by room temperature thermal evaporation of blue-black SnO crystal powder synthesized from metallic tin on glass substrate. X-ray diffractograms revealed that the amorphous samples form polycrystals of SnO when annealed at 300 degree(s)C in ambient air for 30 minutes and are oxidized to polycrystals of SnO2 when further annealed at 500 degree(s)C or above. The 2(theta) of the x-ray diffractogram peaks were produced by (101), (110), (211), (200), (112) planes of SnO and (110), (101), (211), (200), (220) planes of SnO2, respectively, as assigned by the ASTM index. Even though the optical energy gap of SnO (2.4 - 2.6 eV), is smaller compare to that of SnO2 (3.0 - 3.2 eV), the average strength of optical transition is highest for SnO polycrystals with a magnitude of 14.0 eV as compared to 10.4 eV for SnO2. The single oscillator strengths are 4.0 and 3.5 eV for polycrystalline SnO and SnO2 respectively. The plasma frequency was determined to be in the range of (6.1 - 11.8) X 1015 Hz and increases with increasing composition of SnO2; this parameter was used to estimate the density of valence electron in this material.
Film Formation and Analysis
New ion-beam sources and their applications to thin film physics
Show abstract
The development of ion sources for thin film coatings and modifications in the past decade are reviewed. Recent applications for optics and microelectronics are discussed.
Semiconducting Films
Study on the high-field current transport mechanisms in thin SiOxNy films
Bing Liang Yang,
Bai Yong Liu,
D. N. Chen,
et al.
Show abstract
A new model is proposed to explain the current transport behavior in thin thermally nitrided silicon oxide (SiOxNy) films. In this model it was suggested that there are four mechanisms for the current conduction, namely: a) direct electron injection from the cathode; b) current due to electron capturing of traps; c) re-emission of trapped electron; and d) the hole injection from the Si-substrate. The theoretical results of the new model, including the current enhancement and trapping ledge phenomena in the I-V characteristics of the insulators, agree well with the experiments. The influence of the external applied field and the electron traps on the current transport behaviors in the SiOxNy films were also discussed.
High-field electron trapping and detrapping characteristics in thin SiOxNy films
Bing Liang Yang,
Bai Yong Liu,
Y. C. Cheng,
et al.
Show abstract
The electron trapping at high-field and detrapping in thin thermally nitrided silicon oxide (SiOxNy) films were studied in the present work. For lightly nitrided oxide, the effective electron trap concentration was found to increase rapidly with the nitridation duration. In addition, the detrapping ratio of trapped electrons is almost zero and independent of the detrapping time and the applied field strength up to 8 MV/cm. This observation indicates that the increased traps have deeper energy levels. For heavily-nitrided sample, the surface trap concentration decreases and the energy levels of these traps become shallower. The detrapping ratio therefore increases and is an exponential function of the field strength and detrapping time. The detrapping ratio remains unchanged if no external field is applied.
Film Formation and Analysis
Sputtering of silicate glasses
Teruhiko Kai,
Hiromichi Takebe,
Kenji Morinaga
Show abstract
Each of the amorphous films that consists of SiO2, Al2O3, CaO-SiO2, or CaO-Al2O3 system was prepared by rf-sputtering. Changes of film thickness, structure, composition, and transmittance in the visible region depending on the sputtering time were discussed. Especially, the chemical shifts of SiK(alpha) and AlK(alpha) were measured for study of structure and composition of the films by using a high resolution x-ray fluorescence spectrometer with double crystals.
Infrared and Optoelectronic Films
Depopulation kinetics of electron traps in thin oxynitride films
HonLeung Kelvin Wong,
Y. C. Cheng,
Bing Liang Yang,
et al.
Show abstract
his work reports both experimental and theoretical results of the depopulation kinetics of electron traps in silicon oxides annealed in ammonia ambient at a temperature of 1050 degree(s)C for 30, 60, or 180 min. Results show a significant modification of the spatial and energy distribution of traps in oxynitride after employing a heavy nitridation. Specifically, we found that sample with longer annealing duration has large depopulation rate and is more sensitive to the electric field than the sample with a shorter period of annealing. In addition, the nitrided oxides were found to have only a small percentage of traps with shallow energy levels (< 1 eV) and the percentage remains fairly unchanged for different nitridation conditions. However, the deeper traps (> 1 eV) increase significantly as the nitridation proceeds. By considering the re-trapping effect and the spatial and energy distributions of traps, a new depopulation theory of the electron traps in thin oxynitride is developed and most of the experimental observations can be explained with the present model.
Film Formation and Analysis
Multicomponent electric-arc source of metallic plasma
Show abstract
Results of studies carried out during development of a metallic plasma multicomponent electric-arc source and containing eight independently operating cathodes are described. Structural scheme of the developed device and technical characteristics are represented.
Superlattice Films
Application of AlGaAs/GaAs superlattice for negative-differential-resistance transistor
Show abstract
A novel functional resonant-tunneling bipolar transistor (RBT) has been fabricated and demonstrated. In the proposed device, electrons are injected from emitter to base by resonant- tunneling through the minibands in the i-AlGaAs/n+-GaAs superlattice. The main features of the proposed device is the significant double negative-differential-resistance (NDR). Two high peak-to-valley current ratios of 4:1 and 2.6:1 were obtained at 77 K. In the transistor operation, a common-emitter current gain of 60 and a collector offset voltage smaller than more than 0.2 V at 77 K were obtained. As control base current increases sufficiently to cause the base-emitter junction drop beyond flat-band condition, two different transistor action regions with smaller current gains of 38 and 35 are found, respectively. Furthermore, the first peak current is nearly equal to the second peak current and much larger than the second valley current. Therefore, it is attractive to exploit the device in multiple- valued logic circuits and frequency multiplier.
Applications of GaAs grade-period doping superlattice for negative-differential-resistance device
Show abstract
The characteristics of a GaAs graded-period (delta) -doped superlattice grown by molecular beam epitaxy were studied. It is shown that a novel S-shaped negative differential conductivity (NDC) occurred both at 300 K and 77 K. Besides, a two-state avalanche multiplication process, i.e., a middle quasi-stable region is seen at 77 K. Finally, there is an interesting hysteresis phenomenon due to the trapped holes created by the avalanche multiplications. The significant control voltage ratio, Vs/V(Eta) , of the studied structure introduces a good potential for application on the switching field.
Film Formation and Analysis
Formation of Si02 film on plastic substrate by liquid-phase-deposition method
Masaki Kitaoka,
Hisao Honda,
Harunobu Yoshida,
et al.
Show abstract
The silicon dioxide (SiO2) film deposition on a plastic was made by liquid phase deposition (LPD) method. This process involves the deposition and growth of SiO2 layer on the plastic while immersing it in the hexafluorosilicic acid (H2SiF6) solution supersaturated with silica. In this study, it was shown that the specific pretreatment of the plastic surface by silane coupling agent was required for better adhesion of the SiO2 film. And the SiO2 film properties, resistance of organic solvent, water vapor permeability and water absorptivity, were evaluated in order to apply the 'LPD-SiO2' film to the protective layer of the polycarbonate (PC) disk for optical memory. As a result, it was shown that the 'LPD-SiO2' film could improve the properties of the plastic substrate.
Infrared and Optoelectronic Films
Sensitivity and selectivity enhancement in semiconductor gas sensors
Makoto Egashira,
Yasuhiro Shimizu
Show abstract
To date numerous efforts have been made to enhance the sensitivity and selectivity of semiconductor gas sensors to a specific gaseous component. Advantages of these modifications will be discussed in terms of the principle factors in physics and chemistry that are associated with the gas-sensing mechanism of semiconductor gas sensors.
Film Formation and Analysis
Preparation of tin oxide and insulating oxide thin films for multilayered gas sensors
Chang Dong Feng,
Yasuhiro Shimizu,
Makoto Egashira
Show abstract
Crack-free SnO2 and SiO2 films with the controlled thickness up to 1 micrometers have been prepared by the sol-gel spin coating method. Preparation conditions and microstructure of the films are described. Gas sensing elements consisting of single SnO2 thin film and multi-layered SiO2/SnO2 thin films have been prepared using this method. Comparison of sensing properties between single SnO2 thin film and multi-layered thin film sensing elements shows potential advantage for developing selective gas sensors.
GaN single-crystal films on silicon substrates grown by MOVPE
Takao Nagatomo,
Ichiro Ochiai,
Shigeo Ookoshi,
et al.
Show abstract
Single crystal films GaN have been grown on (111) silicon substrates by metal organic vapor phase epitaxy (MOVPE) in an ambient hydrogen gas at atmospheric pressure. When the growth conditions of V/III ratio of 700, growth rate of about 4 micrometers /h and growth temperature from 850 to 940 degree(s)C were maintained, good-quality single crystal films were obtained. The crystal structure of the films is a hexagonal and the (0001) plane of GaN is preferentially oriented on (111) silicon substrates. The properties of the films have been studied by the reflection high energy electron diffraction (RHEED) technique, x-ray diffraction, scanning-electron microscope (SEM), electrical and optical measurements, and photoluminescence.
Surface and Interface
Basis and applicaton of evanescent fluorescence measurement
Y. F. Yuan,
Oliver S. Heavens
Show abstract
Evanescent field fluorescence has recently been used in industry, biology, and medical research work. We present a rigorous electromagnetic theory of evanescent field distributed in layered structure for some different cases. We make use of the fact that stimulated fluorescence is proportional to the local electric field energy. Measuring the relative fluorescence gives the cell-glass separation. Some applications of evanescent field fluorescence are introduced in this paper.
Film Formation and Analysis
Thin film fabrication of stabilized zirconia for solid oxide fuel cells
Toshihiko Setoguchi,
Koichi Eguchi,
Hiromichi Arai
Show abstract
Thin or thick films of YSZ were fabricated by plasma spraying, slip casting, slurry coating, spray pyrolysis, and RF-ion plating methods. A porous electrode substrate of Ni/YSZ cermet anode or La0.06Sr0.4MnO3 cathode was used as a support for YSZ film fabrication. Current-voltage characteristic of hydrogen-oxygen fuel cell with a slurry coated or a slip casted YSZ film was excellent, because these films were dense. The plasma spraying method was most suitable for quick fabrication of cell stacks.
Semiconducting Films
Recent progress in Si thin film technology for solar cells
Yukinori Kuwano,
Shoichi Nakano,
Shinya Tsuda
Show abstract
Progress in Si thin film technology 'specifically amorphous Si (a-Si) and polycrystalline Si (poly-Si) thin film' for solar cells is summarized here from fabrication method, material, and structural viewpoints. In addition to a-Si, primary results on poly-Si thin film research are discussed. Various applications for a-Si solar cells are mentioned, and consumer applications and a-Si solar cell photovoltaic systems are introduced. New product developments include see-through solar cells, solar cell roofing tiles, and ultra-light flexible solar cells. As for new systems, air conditioning equipment powered by solar cells is described. Looking to the future, the proposed GENESIS project is discussed.
Film Formation and Analysis
Optical properties of some ion-assisted deposited oxides
F. Andreani,
S. Luridiana,
Shuzheng Mao
Show abstract
The refractive index of several high index oxide films obtained with ion assisted deposition (IAD) is studied as a function of some ion bombardment parameters. The oxygen/metal ratio of the films obtained with one material (Ta2O5) is also studied. All experiments have been performed on a commercially available large scale production machine.
Structural investigations of the (Si1-x,Gex)O2 single-crystal thin films by x-ray photoelectron spectroscopy
Svetlana Sorokina,
Juriy Dikov
Show abstract
The electron structure of the SiO2-GeO2 single crystal thin films has been investigated by x-ray photoelectron spectroscopy (XPS). The growth of the high-germanium a-quartz was performed under hydrothermal conditions, applying a technique that involves high-alkaline solutions. The quartz crystals with germanium oxide content up to 14 mol% have been obtained for the first time. The XPS experiments were carried out using a photoelectron spectrometer (ES-2401). The XPS data show evidence for high separation of the [SiO4]n and [GeO4]n clusters, because the charged parameters for these atoms are not subjected to mutual excitation to remain close to initial SiO2 and GeO2.
Growth of PbTiO3 films by photo-MOCVD
Show abstract
PbTiO3 films having a perovskite structure have been successfully grown on sapphire, MgO, and Si substrates by the photo-MOCVD technique using tetraethyl lead, titanium tetraisopropoxide, oxygen, and nitrogen dioxide. When O2 was used as an oxidizing gas, polycrystalline perovskite PbTiO3 films were grown at substrate temperatures higher than 600 degree(s)C. UV light irradiation affected the growth rate and crystalline structure. Only when films were grown using the photo-MOCVD method, highly (111) oriented PbTiO3 films were obtained on (0001) sapphire at 600 degree(s)C. When NO2 was used, perovskite PbTiO3 films were grown at a substrate temperature of 530 degree(s)C using the photo- MOCVD method. The use of NO2 in the photo-MOCVD process significantly reduced growth temperature due to its wide absorption wavelength. The electrical properties of films were also measured. The step coverage of films obtained using the photo-MOCVD method was fairly good.
Surface and Interface
Interface stress at thin film semiconductor heterostructures
Taneo Nishino
Show abstract
The interface stress at thin film semiconductor heterostructures has been examined for three technologically important ZnSSe/GaAs, InGaPAs/GaAs, and AlGaAs/GaAs heterostructures. For characterization of the interface stress we have developed a new high-sensitivity method using the characteristic Cr-related luminescence lines in GaAs crystal. Based on a series of experimental results obtained with these three semiconductor heterostructures, the origin of the interface stress has been identified, the results showing that the interface stress in the case of ZnSSe/GaAs is well explained by thermal stress and the interface stress of InGaPAs/GaAs and AlGaAs/GaAs by lattice-mismatched stress.
Semiconducting Films
Deposition of a-Si:H using a supersonically expanding argon plasma
G. J. Meeusen,
Z. Qing,
A. T. M. Wilbers,
et al.
Show abstract
Amorphous Hydrogenated Silicon (a-Si:H) is a material that is widely used in the field of solar cells and other optoelectronics. The only method available to produce high quality a-Si:H is by means of plasma enhanced chemical vapor deposition (PECVD). Radicals responsible for deposition diffuse from a glow discharge toward a substrate that is heated up to 600 K where a layer grows with a speed of typically 0.1 nm/s. The deposition rate is limited because of transport is diffusion determined. An increase of this deposition rate and material efficiency can be expected if the radicals are transported toward the substrate using another transport mechanism.
Surface and Interface
Finite element study on indentations into TiN- and multiple TiN/Ti- layers on steel
H. F. Wang,
A. Wagendristel,
X. Yang,
et al.
Show abstract
A state-of-the-art finite element program (MARCTM) is used to derive as much information as possible from the simulation of a 136 degree(s) wedge indentation into multilayer systems. The deformed specimen is compared with experimentally found results as far as an experiment, i.e., a hardness indentation, yields measurable parameters. We suppose some of the surplus information obtained by the simulation to be reliable as well. A first step is undertaken toward the aim of obtaining elastic constants from a hardness or load-depth measurement in multi-phase films.
Organic and Polymer Films
Ion implantation of polymers for electrical conductivity enhancement
Lynn B. Bridwell,
Yang Wang
Show abstract
Ions in the mass range from H to Xe have been used at energies from a few keV to more than a GeV to cause atomic rearrangement and consequent formation of conducting grains of carbonized material in several polymers. Generally, the conductivity increases dramatically-- by several orders of magnitude--until finally demonstrating a saturation effect with further ion dose. These results indicate that the ion specie, the rate of energy deposition due to electronic processes, and the original structure of the polymer influence the final conductivity of the implanted material. The temperature dependence of the conductivity, in most cases, and frequency dependence in our case indicate a hopping mechanism for the conductivity in a one dimensional mode although precise details of the conducting mechanism are still in question.
Ferroelectric and Dielectric Films
Properties and applications of ferroelectric and piezoelectric thin films
Tadashi Shiosaki
Show abstract
Polar axis oriented films are important in piezoelectric, pyroelectric, optic, and ferroelectric applications. The applications of polar axis oriented films are reviewed. An acousto-optic deflector made of ZnO thin film optics and Si Schottky diode photo-detectors integrated on a Si substrate is described. The properties mainly related to the integrated memory applications of polar axis oriented ferroelectric films grown by reactive magnetron sputtering are reported.
Diamond-like carbon thin films prepared by rf-plasma CVD
Jie Jiang,
Chen Zan Liu
Show abstract
The depositing process, growing rate, structure, and optical properties of Diamondlike Carbon (DLC) films have been studied. It's shown that in the DLC films approximating amorphous carbon and diamond coexist from TED and Raman spectra, and the IR absorption is very low in 2.5 - 14.0 micrometers wavelength range from IR spectrophotometer. The other properties of this films such as chemical, thermal stability, mechanical, and adhesion are discussed. Finally, efficient, durable antireflection and protective coatings on IR optics are described.
Films for Magnetic and Optical Recording
Magnetic steering of energy flow of linear and nonlinear magnetostatic waves in ferrimagnetic films
Show abstract
The magnetostatic waves (MSW) are dispersive in ferromagnetic film wave guide and exhibit wave vector anisotropy so that, in general, the energy flow and wave vector are noncollinear. This paper investigates the dependence of the energy flow direction of linear magnetostatic surface waves (MSSW), volume waves (MSVW), and nonlinear MSSW on the direction of the bias magnetic field H.
Semiconducting Films
Amorphous silicon thin film x-ray sensor
Guang-Pu Wei
Show abstract
Three kinds of amorphous silicon x-ray sensors have been developed. The structures together with some basic characteristics of these sensors are reported. As an example of application, some operational tests for x-ray computed tomography (XCT) have been carried out. The results show that these sensors may provide a variety of potential applications in medical, scientific, and industrial fields.
Optical Films
Study of C-H stretching vibration in hybrid Langmuir-Blodgett/alumina multilayers by infrared spectroscopy
Tian Shui Zheng,
Liying Liu,
Zhongjing Xing,
et al.
Show abstract
Four to six monolayers of aluminum stearate (AlSt3) Langmuir-Blodgett (LB) film and one layer of 3.5 - 6 nm-thick air-oxidized alumina film alternately form an AlSt3/Al2O3 modulated multilayer structure. The AlSt3 monolayers in the hybrid structure is studied by FTIR transmission spectrum and low angle x-ray diffraction. The results show that the alignment of hydrocarbon chains in AlSt3 monolayers is not affected by the fabrication procedure of LB film/alumina multilayer. It suggests that this multilayer-building method may be useful to the study of nonlinear optical properties of LB films.
Superlattice Films
Scaling properties of optical reflectance from quasiperiodic superlattices
Show abstract
The scaling properties of the optical reflectance from two types of quasi-periodic metal- insulator superlattices, one with the structure of Cantor bars and the other with the structure of Cantorian-Fibonaccian train, have been studied for the region of s-polarized soft x-rays and extreme ultraviolet. By using the hydrodynamic model of electron dynamics and transfer- matrix method, and by taking into account retardation effects, we have presented the formalism of the reflectivity for the superlattices. From our numerical results, we found that the reflection spectra of the quasi-superlattices have a rich structure of self-similarity. The interesting scaling indices of the spectra, which are related to the fractal dimensions, are also discussed for the two kinds of the quasi-superlattices.
Superconducting Films
Characterization and preparation of high-Tc YBa2Cu3O7-x thin films on Si with conducting indium oxide as a buffer layer
Z. J. Zhang,
Wei Luo,
Y. Y. Zeng,
et al.
Show abstract
The superconducting YBCO thin films have been successfully prepared by DC magnetion sputtering on silicon substrates with a metallic conductive oxide In2O3 as a buffer layer. The substrate temperature was kept at about 650 degree(s)C during deposition and a subsequent in-situ annealing in oxygen was performed at 450 degree(s)C. The YBCO film on In2O3/Si exhibits zero resistance at 72 degree(s) K. The interface between Si and In2O3 was tested by Rutherford back scattering (RBS) and the characteristics of the YBCO thin films were also examined by x-ray diffraction (XRD).
Ferroelectric and Dielectric Films
Formation of titanium nitride films by Xe+ ion-beam-enhanced deposition in a N2 gas environment
Xi Wang,
Gen Qing Yang,
Xiang Huai Liu,
et al.
Show abstract
A new method in which electron beam evaporation of titanium and bombardment with 40 keV Xe+ ion beam (Xe+-IBED) were done simultaneously in a N2 gas environment, has been developed to prepared titanium nitride films. It was confirmed that the xenon content in the films is very low and the N to Ti elemental ratios of the films approach unit. The films are mainly composed of TiN polycrystalline. The hardness of the films reaches 2200 kgmm-2, higher than that of films prepared by 40 keV N+-IBED. Moreover, some industrial applications of Xe+-IBED titanium nitride films have been reported.
Infrared and Optoelectronic Films
Study of HgCdTe/CdTe interface structure grown by metal-organic chemical vapor deposition
Ke Jun Ma,
Zhen Zhong Yu,
Jian Rong Yanh,
et al.
Show abstract
The interface of HgCdTe/CdTe thin film growth by MOCVD were investigated by high resolution electron microscope (HREM). It is shown that there is no monolayer abrupt interface between HgCdTe and CdTe films. The interface of HgCdTe/CdTe contains a lot of small and random distributed disorder regions. The disorder areas can be transformed into order one under long time electron beam irradiation.
Film Formation and Analysis
New deposition system for the preparation of doped a-Si:H
Zhaoping Wu,
Ru Guang Chen,
Yongling Wang
Show abstract
A novel technique, rf sputtering and rf glow discharge (GD) coexistent system, has been developed for the preparation of doped a-Si:H. Dopant, which is sputtered from the target in either powder or solid, is introduced into GD chamber and then deposited onto the substrate in the presence of glow discharge of silane. The relationship between the deposition parameters and film properties is investigated thoroughly. The substrate negative bias favors deposit of high quality a-Si:H. The conductivity measurement reveals that the Fermi level can be moved from 0.75 eV of undoped a-Si:H to 0.19 eV corresponding to high phosphorous doped a-Si:H by increasing sputtering power.
Semiconducting Films
New process for improving reverse characteristics of platinum silicide Schottky barrier power diodes
Shu-Lan Zhao,
Yuan Jing Li,
Jia Feng Yu,
et al.
Show abstract
This paper reports the use of a unique reactive ion etching (RIE) in Schottky barrier power diode manufacture. Reverse electrical characteristics of conventional Schottky barrier diodes are compared with those of the devices fabricated by RIE. It is shown that such devices give better reverse electrical characteristics eliminating the inherent edge effects of metal- semiconductor contacts. It is also shown that the device yield has been raised to 60%, which is much better than that of conventional Schottky diodes.
Organic and Polymer Films
Ionization potentials effects on CGL/CTL photoconductors
Xiao Dong Shi
Show abstract
This paper presents photoconductive data of several p-type CTL materials--oxazoles, and gives brief discussions concerning their ionization potential Ip and photosensitivity. The Ip values were from the quantum quantitative calculation and the polarographic oxidation potentials, respectively. The photoreceptors using oxazoles as CTL materials showed high sensitivities. A simple correlation was obtained between the Ip values of the CTL materials and the photosensitivities, although the results cannot be explained very clearly.
Infrared and Optoelectronic Films
Optical characterization of Hg1-xCdxTe/CdTe/GaAs multilayers grown by molecular beam epitaxy
Show abstract
The IR transmission spectra for HgCdTe/CdTe/GaAs multilayers grown by molecular-beam epitaxy were measured in the wavenumber region of 600 cm-1 - 4000 cm-1 at 300 K and 77 K. The transmission spectra were calculated taking the thickness d1 of MCT layer and the thickness d2 of CdTe layer as fitting parameters in the energy range from 600 cm-1 to 300 cm-1 below the energy gap Eg assuming the existence of abrupt interfaces between the neighboring layers. The values of d1 and d2 obtained by fitting the IR transmission spectra are in good agreement with that by transmission electron microscopy (TEM) measurement. The accurate absorption coefficient spectra were obtained and discussed in the energy region equivalent to 0.9 Eg to 4000 cm-1 taking into account the interference effects.
Determination of thickness and refractal index of HgCdMnTe/CdMnTe VPE films by IR transmission spectrum
Wei Min Chen,
Ke Jun Ma,
Zhen Zhong Yu,
et al.
Show abstract
The thickness and refractal index of the diluted magnetic semiconductor (DME) Hg1-x-yCdxMnyTe thin films grown on Cd1-zMnzTe substrate by close-spaced isothermal vapor phase epitaxy (ISOVPE) technique had been determined by the method of fitting the theoretical infrared transmission spectrum to the experimental data. The range of the film thickness was 5 - 30 micrometers and the indexes were around 3.5, depending upon the compositions. The index of Cd1-xMnzTe was also obtained by the combination of mechanical thinning and optical measurements, which changes from 2.71 (z equals 0.1) to 2.88 (z equals 0.6), and compared with those of related II-VI materials, CdTe and HgCdTe. The method was verified by scanning electron microscope data. It is non-destructive, simple, and effective, and can be routinely used in thin film material characterization.
Film Formation and Analysis
Transition radiation in foil stack and x-ray laser
Zu Q. Yan,
Keifei Fei Ruan
Show abstract
This paper discusses some questions about transition radiation and the possible model using transition radiation system to produce x-ray lasers.
Ferroelectric and Dielectric Films
Preparation and magneto-optical properties of NdDyFeCoTi amorphous films
Si Jun Zhang,
Xiao Yong Yang,
Xiaowen Li,
et al.
Show abstract
Amorphous NdDyFeCoTi films were prepared by RF magnetron sputtering onto glass substrates at zero bias, low Ar pressure of 3 - 7 mTorr and low input sputtering power of 100 - 300 W. They were overcoated by a SiO2 protective layer. The magnetic and magneto- optical properties of these films were studied by VSM, Kerr hysteresis tracer, Auger electron spectrum, and electron microprobe. The Kerr angle (theta)k of 0.3 degree(s) and the coercive force Hc of 3 - 5 KOe have been found. The stability of the films was examined by exposure in dry air for one month and annealing at 100 - 250 degree(s)C. The coercive force Hc changed with the film thickness. It was found that the preparation conditions had obvious effects on the structure and properties of the film. The Ar pressure and substrate bias voltage affected the microstructure, magneto-optical properties, and the stability. The films prepared under these conditions have dense, smooth, featureless, highly disorder amorphous structure without any obvious void and columnar microstructure. The aging experiment showed that these films had good oxidation and corrosion resistance. The NdDyFeCoTi films prepared under optimal conditions exhibited excellent magneto-optical recording performance with recording laser power of 5 mW and applied magnetic field of 500 Oe.
Films for Magnetic and Optical Recording
Multistable magnetostatic waves in thin film
Show abstract
A theory of the propagation of nonlinear magnetostatic surface waves in a ferromagnetic film with a periodically corrugated surface is presented. It is shown that the filter characteristics of this nonlinear periodic structure exhibits bistable or multistable properties above a threshold power so that, for a given input power of the wave, several values of output power are possible.
Infrared and Optoelectronic Films
Incorporation of As into HgCdTe grown by MOCVD
Jin He,
Zhen Zhong Yu,
Ke Jun Ma,
et al.
Show abstract
This is the first report on the mechanism of As incorporation into MOCVD-grown HgCdTe/CdTe/GaAs films. HgCdTe/CdTe/GaAs wafers have been grown by metalorganic chemical vapor deposition (MOCVD). The atomic absorption spectrometer was utilized to analyze As content in the As-grown HgCdTe epilayers. The integrated GC-MS analytical system was utilized to observe the decomposition products of DMCd and/or DETe at different temperatures in the presence of GaAs. The mechanism of As incorporation into epilayers is presented.
Semiconducting Films
Thermal stabilities of a-Si:H films and its application to thyristor elements
Yue Zhen Sun,
Chun Xian Chen,
Qi Yao Xie,
et al.
Show abstract
We report on hydrogenate amorphous silicon (a-Si:H) films as unique passivation films for crystal silicon (C-Si) devices used on the thyristor elements. It's shown that a-Si:H passivation films could be used to raise the forward and reverse breakdown voltage over a wide range, as well as to improve the high temperature feature for thyristor elements. There are economic results. The a-Si:H passivation films have a novel ability to attract the impurities from the interface of c-Si device to the a-Si:H films and promote the c-Si devices with high quality. We also discuss the thermal stability of a-Si:H passivation films.
Infrared and Optoelectronic Films
New appproach to colored thin film electroluminescence
Xurong Xu,
Gang Lei,
Zheng Xu,
et al.
Show abstract
The priority of TFEL compared with LCD in their intrinsic properties is shown. The possibility to obtain colored thin film electroluminescence by means of using a novel EL structure, with selected materials and CL phosphors is revealed. Higher hot electron energy and multiplication factor provide the necessary conditions.
Film Formation and Analysis
Growth of rf-sputtered selenium thin films
Xiang Long Yuan,
Szuk Wei Min,
Zhi Yao Fang,
et al.
Show abstract
The growth process of selenium thin films deposited by RF sputtering on slide glass was investigated for various substrate temperatures by SEM. Droplet growth was observed at substrate temperature higher than 30 degree(s)C. The droplet density decreased but the size increased with increasing temperature. A thin layer under droplets was obtained that might be caused by secondary electro bombardment and radiation from the plasma and/or the contamination on substrate surface. The effect of substrate temperature on the growth of the thin layer was discussed.
Films for Magnetic and Optical Recording
Dispersion of nonlinear magnetostatic surface waves on thin films
Show abstract
The wave equation of nonlinear magnetostatic surface waves (MSSW) on ferromagnetic films is derived for the first time and its solution is found. The nonlinear dispersion relation of MSSW is discussed.
Organo-metallic thin film for erasable optical recording medium
Show abstract
An erasable optical recording medium was made by vacuum deposition of copper tetra cyanoquino dimethane organometallic materials writable and erasable with an He-Ne laser. With He-Ne laser output power of 13 mW at 632 nm, the threshold pulse width was 0.2 - 2 microsecond(s) . The readout signal contrast was 29%. The write-erase cycles were observed under optimum condition.
Ferroelectric and Dielectric Films
Specific properties of ferroelectric thin films
Weiguo Liu
Show abstract
Ferroelectric thin films have some specific properties such as low dielectric constant, high coercive force and presenting of polarization above Curie point, etc. These properties can be explained by the existence of surface layer and internal stresses in the films. The surface layer has lower dielectric constant and large spontaneous strain than in the bulk. The internal stresses will cause the shift of Curie point and create an internal bias field in the films.
Surface and Interface
Research on the temperature of thin film under ion beam bombarding
Yun-Fei Zhao,
Shuzi Sun,
Shi Jin Pang
Show abstract
Temperature measurement of thin films under ion beams bombardment has been made by a new method. 100 Kev Ar ion have been used to bombard the Al thin films deposited on Fe8Co39Ni31Si6B16 non-crystal thin straps. Several data of the temperature were obtained indirectly by analyzing the substrate by means of DTA. When the intensity of the ion beams were 5 W/cm2 and 12 W/cm2, the temperatures were 700 K and 806 K. Starting from the conservation of energy in equilibrium state, a theoretical equation has been derived. Chosen reasonable approximation, the theoretical curve of the temperature depending on the ion beam power comparatively conforms the experimental results.
Infrared and Optoelectronic Films
Study of p-ZnTe/n-CdTe thin film heterojunction
Ping Wu
Show abstract
From band theory, this paper analyzes the junction region structure of p-ZnTe/n-CdTe heterojunction and offers the energy band figure. In the junction region, the bottom of the conduction band is noncontinuous and the top of the vanlence band has a convex peak in p- region and a concave peak in n-region. This thesis also analyzes the conduction of the heterojunction by the diffusion model. With thermal balance, the barrier for the pyieldsn holes in the vanlence band is lower than that for the nyieldsp electrons in the conduction band. So, the holes conduction is main and the electronic conduction can be negligible. The experimental method and the technological process of the heterojunction are described. And the results are given.
Organic and Polymer Films
Defects in SIPOS film studied by ESR
Yun Zhen Wang,
Yao Ling Pan
Show abstract
In the present paper, we used the data of g-factor value, linewidth Hpp, and spin density Ns from ESR measurement to investigate the defects in SIPOS film. There are four defects related to the different Si tetrahedral structures Si - (Si4 - YOY) in SIPOS film. These defects are named defect 1, defect 2, defect 3, and defect 4. The ESR spectrum found for a specific oxygen content is assumed to be a linear superposition of the resonance of these four defects. The g-value is the statistical average of four g-values' corresponding defects. Using the above model of defects, the variations of linewidth and spin densities of SIPOS film with different oxygen content and annealing conditions can be well described.
New results on proton nuclear magnetic resonance of a-SiN:H films
Ji Shen Wang,
Chun Fang Xu
Show abstract
In this paper, results of proton magnetic resonance for hydrogenated amorphous silicon nitrides (PECVD a-SiN:H) films are presented. The results are different from those previously reported by other authors.
Superlattice Films
Single crystallinity and oxygen diffusion in high-quality YBa2Cu3O7-delta films
Show abstract
High quality epitaxial YBa2Cu3O7-(delta) films prepared by d.c. magnetron sputtering are single crystalline containing mosaic blocks, the boundaries of which consist of arrays of dislocations piling up into walls. Low temperature oxygenation in the orthorhombic phase is carried out by pipe diffusion in the basal planes. An equation has been derived from the dislocation model of low angle tilting grain boundary which predicts a linear relationship between the oxygen increase 1-(delta) and t3/4, where t is the diffusion time. Two straight lines were established for oxygen anneal respectively at 300 degree(s)C and 350 degree(s)C and these verified the proposed model explicitly. From slops of these two straight lines, an activation energy of 1.18 eV for lattice diffusion of oxygen is obtained.
Organic and Polymer Films
Charge buildup in polypropylene thin films
Hai Ding
Show abstract
Irradiation of insulating polymer films with nonpenetrating electron beams results in lasting space charge. The charge-storage properties of polymer electrets are the most important for their application. The location of the charge and the radiation-induced conductivity are interesting both for production of foil electrets and for the investigation of charge phenomena in such materials. In this paper, charge buildup in 30 micrometers thick films of polypropylene irradiated with monoenergetic electron beams of 10 to 45 KeV energy is investigated. Using the split-Faraday cup, the mean charge depth at the beginning of electron injection, at the termination of injection, and 10 minutes after the injection are measured. It is found that the depth increase with time during charging, but decreases a little after the injection of electron beams. The charge depth also increases with the amount of injected charge. From the dynamics of charge motion during irradiation, the radiation-induced conductivity is determined as a function of dose rate.
Film Formation and Analysis
Studies of InSb metal oxide semiconductor structure fabricated by photo-CVD using Si2H6 and N2O
Show abstract
Silicon oxide films (SiOx, O2H6) with nitrous oxide (N2O) at temperature below 200 degree(s)C using 2537 A ultraviolet (UV) light. Ellipsometric studies prove that the refractive index and etching rate of the photo-oxide depend on the substrate temperatures and gas ratio. Composition and electrical properties of the interface (SiOx/InSb) are discussed by using Auger electron spectroscopy (AES) and metal-oxide-semiconductor capacitors. Hysteresis free capacitance- voltage (C-V) characteristics measured at 77 K are attained and the minimum interface state density is only 1.5 X 1011 cm-2eV-1.
Optical Films
Effect of oxygen on optical properties of yttria thin films
Xuantong Ying,
Albert Feldman,
Edward N. Farabaugh
Show abstract
A series of yttria optical thin films was prepared under different oxygen partial pressures by electron beam evaporation. A multiparameter nonlinear curve fit method was used to determine the refractive index, absorption coefficient, and thickness of these films. The experimental result indicates the partially oxidized materials inside the films that reduce the transmittance of the films could be oxidized by oxygen backfilled into deposition chamber during the evaporation process to produce optical yttria thin films with low absorption coefficient.
Optical properties of granular Sn films with coating Al
Guangming Wu,
Zheng Xing Qian
Show abstract
Optical properties of the granular Sn films with coating Al films are studied. The experimental results indicate that the Al coating strongly affects the optical properties of the granular Sn- films, the spectral selectivity of the solar energy in the visible region and the reflectance in the near IR region are enhanced. The filling factor Z of granular Sn films obviously influences the optical properties of the film system. Based on the installed structural model and Maxwell- Garnett theory, the reflective spectra are calculated and the theoretical results fit the experimental ones very well. It's show that the granular Sn films coated with Al have some kind of reflective color, it may be used as decorative mirrors for many purposes.
Dependence of optical properties of thermal-evaporated lead telluride films on substrate temperature
Weiting Feng,
Yixun Yan,
Cui Yuan Zhu
Show abstract
New results on the optical properties of lead telluride films are reported. Semi-transmitting PbTe films were prepared by thermal evaporation. It is demonstrated in detail that substrate temperature during deposition significantly influences the optical properties of PbTe films. The results indicate that PbTe films have the minimum absorption and maximum indices of refraction when deposited at the substrate temperature of 170 degree(s)C and 230 degree(s)C, from wavelengths of 4 to 15 micrometers .
Films for Magnetic and Optical Recording
Magneto-optical Kerr rotation of thin ferromagnetic films
H. R. Zhai,
Y. B. Xu,
M. Lu,
et al.
Show abstract
The magneto-optical Kerr rotation of thin ferromagnetic film (Co, Ni, and Fe) is studied experimentally and theoretically. The Kerr rotation of magnetic/air structures is found to be enhanced a lot even when the thickness of magnetic layer is very small. Numerical calculation also indicates that if a thin magnetic layer is sandwiched between two dielectric layers of the same optical constants, the Kerr rotation does not drop as the thickness is decreased.
Surface and Interface
Interface properties of a-C:H/a-SiOx:H multilayer
Show abstract
The a-C:H/SiOx:H multilayers were prepared by rf magnetron sputtering. Small angle x- ray diffraction, Auger depth profile shows periodicity of the films very well. The interfacial roughness parameters (xi) determined by the x-ray diffraction is 0.49 nm, the interface width di obtained from Auger depth profile ranges from 0.78 nm to 1.1 nm. The infrared spectroscopy shows Si-C bond vibration absorption at interface.
Superlattice Films
Amorphous silicon periodic and quasiperiodic superlattices
Show abstract
The a-Si:H based compositional periodic and quasiperiodic superlattices (SLs) have been investigated by low-angle x-ray diffraction, Auger electron spectrum (AES), and cross-section TEM micrograph experiments. We show that most of the structures have sharp and smooth interfaces to better than 6 angstrom. The results also indicate that the peculiarities of quasiperiodic a-Si:H SLs are very different from those of periodic structures. The quantum size effects in a-Si:H SLs has been verified by the wavelength differential absorption (WDA) spectrum measurements.
Semiconducting Films
Study of the microstructures in Ar+ laser crystallized films of a-Si:H for active layer of thin film transistors
Xinfan Huang,
Xiang Dong Zhang,
Wei Ying Zhu,
et al.
Show abstract
The structural and electrical properties of a-Si:H crystallized films obtained by the Ar+ laser scanning irradiation have been investigated by means of Raman scattering, X-ray diffraction, and conductivity-Hall measurement. For the liquid phase laser crystallized films (LP-LCR) the results show that the average grain size is about tens of micrometers and the preferential crystal orientation is in the direction of <111>. At room temperature the conductivity of crystallized films is 1.5 ((Omega) (DOT)cm)-1 and the Hall mobility of electrons is about 36 cm2/V(DOT)s.
Infrared and Optoelectronic Films
Preparation of Pb1-xGexTe crystal with high refractive index for IR coating
Su-ying Zhang,
Bu-Yun Xu,
Fengshan Zhang,
et al.
Show abstract
The Pb1-xGexTe crystal (Pb1-xGexTe multilayer is higher than that of PbTe multilayer. The edge collapse is less for Pb1-xGexTe when the multilayer is cut by the diamond blade.
Superlattice Films
Ion implantation of diamond-like carbon films
Jin Zhong Xiang,
Zhi Hao Zheng,
Changgeng Liao,
et al.
Show abstract
Diamond-like carbon (DLC) films (a-C:H) were implanted by 140 keV and 110 keV Ar ion beams. The characteristics of the implanted films decreased dramatically under a dose of 2 X 1016 Ar/cm2. IR spectra and optical gap Epot were measured. It was found that the SP2 and SP3 components decreased due to the loss of hydrogen during implantation, and the ratio of components SP2 bonds to SP3 bonds increased with the ion dose. And the optical gap Epot decreased from 1.46 eV to 0.83 eV. The hydrogen (bonded and unbonded) contents in the films were measured with the nuclear resonant reaction 1H (19F,) 16O. It is shown that hydrogen plays an important role in affecting some properties of DLC films.
Films for Magnetic and Optical Recording
Variation of optical properties of gel-derived VO2 thin films with temperature
Show abstract
VO2 thin films are prepared on three kinds of substrates by the sol-gel dip-coating method followed by heat treatment under vacuum conditions. The IR and UV-visible spectra of the films are studied during heating and cooling between room temperature and 100 degree(s)C. The experimental results show that the films exhibit thermally-induced reversible phase transition and, as a result, the maximum changes in transmittance and reflectivity are 58% and 25%, respectively, in the case of vacuum heat treatment at 400 degree(s)C and silica glass substrates. The refractive index n decreases and the extinction coefficient k increases when heating these films from room temperature to 100 degree(s)C, and vice versa. The reasons why the optical constants and IR absorption spectra change so remarkably are discussed.
Optical Films
Fabrication of cold light mirror of film projector by direct electron-beam-evaporated TiO2 and SiO2 starting materials in neutral oxygen atmosphere
Di Sheng Zhong,
Guang Zhong Xu,
Wi Liu
Show abstract
This paper introduces a process suitable to applied production of a cold light mirror of a film projector on a large scale. Deposition parameters required for producing a TiO2/SiO2 optical multilayer systems by electron beam evaporation of TiO2 and SiO2 starting materials are investigated. Manufacture and techniques of a cold mirror and the adhesion, stability, wear, and corrosion resistance of a cold mirror by this process are discussed. The results show that cold mirrors have good optical properties and better adhesion.
Ferroelectric and Dielectric Films
Surface normal SHG in PLZT thin film waveguides
Show abstract
The use of a PLZT thin-film waveguide for surface normal second harmonic generation (SHG) has been theoretically investigated. The necessary conditions for surface normal second harmonic generation are described. The polycrystalline nature of the film poses no disadvantages for this application beyond the increase in scattering losses.
Film Formation and Analysis
Thin film SIMNI material formed by low energy nitrogen implantation and epitaxial growth
Chenglu Lin,
Jinhua Li,
Zou Shichang
Show abstract
N-type <100> Si wafers were implanted with 95 keV, (0.1-1) X 1018/cm2 N+2 and N+ by using ion implanter without mass analysis. After implantation the samples were annealed at 1200 degree(s)C for 2 hours and underwent vapor phase epitaxial growth. Some of the physical and electrical properties of the thin film SIMNI materials were studied by Rutherford backscattering and channeling, cross- sectional transmission electron microscopy, Auger electron spectrometry, infrared absorption and reflection, and spreading resistance measurements. All the results showed that thicknesses of top silicon layer with minimum channeling yield of 5% are 0.3 - 1.0 micrometers and the thicknesses of buried Si3N4 layer are 170 - 200 nm. The Si-Si3N4 interfaces are extremely abrupt. In order to obtain the good SIMNI material, the ion implantation dose is an important parameter, which has a great influence upon the quality of the top silicon layer.
Superlattice Films
High-quality heavily strained II-VI quantum well
Show abstract
Atomic layer epitaxy technique was successfully applied to grow CdTe-ZnTe multilayers on (001) GaAs substrate. A structure of (CdTe)m(ZnTe)n-ZnTe multiquantum wells was proposed and prepared, and characterized by x-ray diffraction, photoluminescence, and modulation reflection spectroscope. The high crystalline quality is mainly due to the reduction of misfit dislocations.
Ferroelectric and Dielectric Films
Small polaron conduction in amorphous CoMnNiO thin film
Hui Tan,
Mingde Tao,
Dong Gin,
et al.
Show abstract
CoMnNiO thin film deposited by rf sputtering is a combination of various amorphous metal oxides. Its DC conductivity changes smoothly with temperature from 173 to 373 K. The relation of AC conductivity with frequency can be written as (sigma) ((omega))∝(omega)s. Its thermopower is positive and its mobility at 330 K is about 1.25 cm2V-1S-1, which is thermally activated. It can be inferred that small polaron conduction is included in the conduction of this amorphous thin film.
Superlattice Films
Effect of parameter variation on the performance of InGaAsP/InP multiple-quantum-well electroabsorption/electrorefraction modulators
Feike Xiong,
Long D. Zhu,
C. M. Wang
Show abstract
The dependence of electroabsorption and electrorefraction in InGaAs/InP multiple-quantum- well (MQW) structures on the MQW parameter (as P mole fraction y, well thickness Lz, residual impurity concentration Ndj in i region, and interface quality) and on the applied electric field is investigated theoretically. The relationship between the performance of a MQW long-wavelength phase modulator and electro-refraction is also investigated. Our theoretical study shows that the In1-xGaxAsyP1-y/InP MQW structure with y equals 0.9, Lz equals 100 angstrom is appropriate for a intensity modulator and the structure with y equals 0.87, Lz equals 140 angstrom is suitable for a phase modulator. High interface quality and low i region residual impurity concentration are in favor of the fast and efficient MQW modulators.
Optical Films
Optical thin film devices
Shuzheng Mao
Show abstract
Thin film devices are applied to almost all modern scientific instruments, and these devices, especially optical thin film devices, play an essential role in the performances of the instruments, therefore, they are attracting more and more attention. Now there are numerous kinds of thin film devices and their applications are very diversified. The 300-page book, 'Thin Film Device and Applications,' by Prof. K. L. Chopra gives some general ideas, and my paper also outlines the designs, fabrication, and applications of some optical thin film devices made in my laboratory. Optical thin film devices have been greatly developed in the recent decades. Prof. A. Thelan has given a number of papers on the theory and techniques, Prof. H. A. Macleod's book, 'Thin Film Optical Filters,' has concisely concluded the important concepts of optical thin film devices, and Prof. J. A. Dobrowobski has proposed many successful designs for optical thin film devices. Recently, fully-automatic plants make it easier to produce thin film devices with various spectrum requirements, and some companies, such as Balzers, Leybold AG, Satis Vacuum AG, etc., have manufactured such kinds of coating plants for research or mass-production, and the successful example is the production of multilayer antireflection coatings with high stability and reproducibility. Therefore, it could be said that the design of optical thin film devices and coating plants is quite mature. However, we cannot expect that every problem has been solved, the R&D work still continues, the competition still continues, and new design concepts, new techniques, and new film materials are continually developed. Meanwhile, the high-price of fully-automatic coating plants makes unpopular, and automatic design of coating stacks is only the technique for optimizing the manual design according to the physical concepts and experience, in addition, not only the optical system, but also working environment should be taken into account when designing optical thin film devices. Therefore, chemical and mechanical, as well as optical properties of thin films and optical system, should be known. Following is the outline of design method and applications of optical thin film devices according to the classification of our factory, Shanghai Optical Instrument Factory.
Organic and Polymer Films
Langmuir-Blodgett films of tetra-tert-butyl-phenoxy phthalocyanine iron [II]
Show abstract
Homogeneous Langmuir-Blodgett (LB) films of Tetra-Tert-Butyl-Phenoxy Phthalocyanine Iron [II] were transferred onto solid plates by Z-type deposition. The optical characterization and structure of films were investigated in detail. The results of the molecular areas of monolayers and the film thickness of the multilayers measured by x-ray diffraction indicated that phthalocyanine macrocycles were oriented nearly perpendicular to the substrate surface. The polarized infrared spectra of the thin films confirmed the orientational order. The effect of temperature on the LB films was examined.
Film Formation and Analysis
Thin films of solid electrolytes and studies of their surface
Xiaoren Pan,
Zhi Xia Gu
Show abstract
Much research work has been done on the materials of solid electrolytes and their applications. Solid electrolytes or fast ionic conductors are generally used in solid state batteries and solid state ionic devices. In the utilization of solid electrolytes, thin film forms have practical advantages. They will make the devices and batteries miniaturization which is particularly important for certain applications such as microelectronic devices, space programs, and integrated circuits of self-contained power. So preparation of thin films of solid electrolytes and studies of their surfaces are significant. There has been interest in the properties of amorphous ionic conductors, as glasses have acknowledged advantages over crystalline electrolytes, including physical isotropy, the absence of grain boundaries, and continuously-variable composition. Furthermore, many glasses based on silver halides have conductivities as high as 10 Scm-1 at room temperature. So we have chosen the quaternary system AgI-Ag2O-P2O5-B2O3 as the basic materials, prepared thin films, studied their properties, and constructed thin film electrolytic batteries.
Superlattice Films
Growth of ZnSe-ZnTe strained-layer supperlattices by atmospheric pressure MOCVD on transparent substrate CaF2 (111)
Chuan Kang Pan,
F. Y. Jiang,
Guang Han Fan,
et al.
Show abstract
ZnSe-ZnTe strained-layer superlattices were grown by atmospheric pressure MOCVD on transparent substrate CaF2(111) for the first time. With x-ray diffraction measurements, multi- order satellites were observed, which confirms the formation of the period structure of superlattices. Photoluminescence measurements were carried out at 77 K with the excitation of the line (337. 1nm) of N2-laser. Optical absorption measurements were performed at room temperature with UV-3000 Double-Wavelength/Dual Beam Recording Spectrosphotometer.
Film Formation and Analysis
Boron depth profiles in a-Si1-xCx:H(B) films after thermal annealing
Changgeng Liao,
Zhi Hao Zheng,
Yong Qiang Wang,
et al.
Show abstract
B-doped hydrogenated amorphous silicon-carbon [a-Si C:H(B)] film is an important photovoltaic material owing to its wide band gap. During the past years it has attracted much attention and has been used in some devices such as solar cells. At present, however, there have been few reports of detailed results about the thermal stability of a-Si1-xCx:H(B) films. Therefore, the determination of boron depth profiles in these films after thermal annealing and related properties are of interest. In this report, the measurements of B depth profiles in p-layer of a-Si:H/a-Si1-xCx:H(B)/a-Si:H films after thermal annealing at various temperatures Ta were carried out by using B(p,(alpha) )8 Be resonant reaction at Ep equals 163 keV. The distribution shapes of boron concentration in these films and some characteristics are presented.
Superconducting Films
Microwave properties of YB2Cu3O7-x thin films characterized by an open resonator
Shi Ping Zhou,
Ke Qin Wu,
A. Jabbar,
et al.
Show abstract
We have performed millimeter-wave frequency (94 GHz) measurements on high quality YBa2Cu3O7-x superconducting films on yttrium stabilized (100) ZrO2, MgO substrates. The 0.2 micrometers thin films fabricated by the magnetron sputtering in- situ technique with the YBa2Cu3O7-x powders as the target exhibit superconducting transition temperature up to 88 K, critical current density of 6 * 105 A/cm2 77 K. X-ray diffraction spectrum, as well as scanning electron microscope photos, indicate these thin films are fully c-axis oriented, extremely high in density, and universally homogeneous. Millimeter-wave surface resistances have been measured on a hemisphere open resonator in the temperature range of 20 K to Tc and beyond. Surface resistance value at 94 GHz and 77 K for these films are found to be about 30 m(Omega) , nearly 1/4 as that for copper, and a two orders drop in the surface resistance within 4 K is observed. That indicates these films to be good materials for the application in millimeter- wave range, especially for fabricating microwave devices. We observed such low surface resistance in these thin films by virtue of the near absence of grain and phase boundaries in these films coupled with their high degree of crystalline orientation.
Ferroelectric and Dielectric Films
Standing spin wave modes in permalloy-FeCr multilayer films
H. Y. Chen,
Y. Q. Luo
Show abstract
Permalloy-FeCr multilayer films have been investigated by ferromagnetic resonance experiments. The behavior of standing spin wave modes shows the influence of exchange coupling between magnetic layers.
Superconducting Films
Preparation of thin superconducting YBCO films by ion-beam mixing
Xiang Jun Fan,
You Gui Pen,
Huai Xi Guo,
et al.
Show abstract
In this paper, we present a new method using ion beam mixing to prepare thin superconducting YBCO films. In the high-low temperature target room, multilayered Y-Ba-Cu films were prepared by multi-evaporation. Then the multilayered films were mixed by ion beam. After annealing, superconducting films with zero resistance temperature at 80 K can be obtained. The constituent determined by electron probe microanalysis (EPMA) is close to the 1-2-3 case. X-ray diffraction patterns show that the structure of the film is orthorhombic having an obvious c-axis orientation perpendicular to the film surface like the epitaxial films.
Optical Films
AR layer properties for high-power laser prepared by neutral-solution processing
Show abstract
The AR layer prepared by chemical method is of renewed interest due to its higher laser damage threshold than that of AR film deposited by the vacuum evaporation method. The AR layer has been prepared on BK-7 glass substrate by neutral-solution processing in our laboratory and the results were reported in 1989. Recently, we improved the preparated condition that the transmittance increase from 99% at 1.06 micrometers and the laser damage threshold still remain about twice as the AR film prepared by vacuum evaporation method. The cross structure of the AR layer has been observed by TEM.
Semiconducting Films
Silicon nitride film formed by NH3 plasma-enhanced thermal nitridation
Zhi Guang Gu,
Bing-Zong Li
Show abstract
Recently, with the rapid development of VLSI microelectronics, the device dimension is reduced to micron and submicron range. The thickness of the dielectric film is reduced to 10 nm. The very thin SiO2 often shows high leakage current, low breakdown voltage, poor capability of resisting the penetration of impurities, and instable physical properties. It is one of the important subjects of semiconductor microelectronics technology to improve the properties of the SiO2 used in fabrication of VLSI devices. In this work, an NH3 plasma enhanced thermal nitridation (NPTN) technique is investigated to improve the quality of thin dielectric films.
Film Formation and Analysis
Investigation into the characteristics of a-C:H films irradiated by electron beam
Shulin Gu,
Yuliang L. He,
Zhi Chao Wang
Show abstract
The characteristics of a-C:H films irradiated by different doses of electron beam have been studied by x-ray diffraction. IR absorption, Raman scattering, and resonant nuclear reaction. Such irradiation can lead the structure of a-C:H films to change in a different degree. The proportions of diamond crystalline and graphite structures in a-C:H films have a proper change simultaneously. The experimental results show a relationship to the action of hydrogen and a proper explanation is given.
Surface and Interface
Characterization of GaAs thin films grown by molecular beam epitaxy on Si-on-insulator
Wen Hua Zhu,
Chenglu Lin,
Yue Hui Yu,
et al.
Show abstract
The direct growth of GaAs by molecular-beam epitaxy (MBE) on silicon-on-insulator (SOI) structure is presented. Rutherford backscattering and channeling (RBS/C), transmission electron microscope (TEM), and infrared (IR) reflection measurements have been employed to characterize the GaAs thin films. RBS/C results show that there is considerable lattice disorder at the GaAs-Si interface, but the crystal quality of the GaAs thin films improves remarkably toward GaAs surface for thicker films where the minimum channeling yield drops to 10% IR reflection spectra in the wavenumber range 1500 - 5000 cm-1 were measured for GaAs thin films on SOI. Interference fringes observed in IR reflection spectra also prove that the crystalline GaAs thin films have been deposited on SOI substrates. By computer simulation of the IR reflection interference spectra refractive index profiles of the GaAs/SOI structures were obtained.
Film Formation and Analysis
Investigation on the anomalous structure of the nanocrystal Ti and Zr films
W. Shi,
J. Kong,
H. Shen,
et al.
Show abstract
The nanocrystal Ti and Zr films were prepared by dc magnetron sputtering method on a liquid N2 cooled copper substrate using Ti and Zr metal targets, respectively. The grain size of the Ti and Zr films is in the range of 5 - 12 nm, determined by both TEM observation and x- ray diffraction patterns using Warren-Averbach analysis. The structure anomaly for Ti and Zr films are found by means of electron diffraction as well as x-ray diffraction. The results of x- ray diffraction show that they are typical bcc structure for Ti films, which appears only at high temperature (more than 885 degree(s)C). The tattice parameter is 0.33178 nm close to that of the diffraction data extended from Ta-Ti alloys (JCPDS-5-628). For Zr nanocrystal films, the x-ray diffraction patterns show that it is (omega) -phase which appears only at high pressure above 39 kbar.
Surface and Interface
Simulation of local layer-thickness deviation on multilayer diffraction
Show abstract
Recent investigation on multilayer films with a local layer-thickness deviation has been performed. This kind of deviation may occur at any position in the multilayer. Simulated example of W/C, W/Si, and Pd/Si multilayers for CuK(alpha) and CuL(alpha) diffractions with different layer parameters as well as various amounts of the local deviations show quite different behaviors. The results show that the diffraction profile for a local deviation A' equals A+ (Delta) d or B' equals B+ (Delta) d is nearly antisymmetric to that for A' equals A- (Delta) d or B' equals B- (Delta) d and the appearance of double peaks is affected by both of the position and amount of the local deviation. Explanation has been carried out by the amplitude-phase diagrams.
Films for Magnetic and Optical Recording
Recording and erasing characteristics of GeSbTe-based phase change thin films
Lisong Hou,
Chuanxing Zhu,
Donghong Gu
Show abstract
GeSbTe-based thin films are prepared by both evaporation and sputtering methods. By the optimization of the film thickness the erasing (crystallization) time of some films is less than 100 ns and the contrast can be as high as 25%. Both the amorphous and the crystalline states of the unprotected films are stable up to 104 writing/erasing cycles. The employment of a fourth element significantly improves the cycling stability up to 105 times.
Surface and Interface
Magneto-optical studies of n-type Hg0.622Cd0.378Te grown by molecular beam epitaxy
Show abstract
Magneto-photoconductivity of n-type Hg0.622Cd0.378Te/CdTe/GaAs samples grown by molecular-beam epitaxy (MBE) was measured in the wavenumber region of 400 - 5000 cm-1 at 4.2 K by the Fourier transform magneto-optics system. The highest magnetic field used was as high as 8 Tesla. The experimental results were interpreted in terms of quasi-Ge model of Pidgeon and Brown. Our results show that this model is still valid for Hg1-xCdxTe with composition x as high as 0.378.
Optical Films
Study on the mechanism of ZnS antireflecting coating with high strength
Ju Xian Yu,
Jia Tian Tang
Show abstract
It has been considered formerly that the reason why ZnS coating is not able to stand the environmental corrosion is the cross section structure of its column,1 the gaps among the columns and the capillaries formed by the gaps. The gaps among the columns of ZnS coating deposited on the substrate at low temperature are rather big, the packing density is low, so the coating can not have better mechanical pro— perties.2 To obtain ZnS coating with high strength it is necessary to enhance the temperature of the substrate during deposition. But the problem is that the higher the temperature is, the lower the deposition - speed will be. 200°C is nearly the temperature limitation of the substrate at which the deposition can be done. This fact also hinders us to enhance the strength of the coating. Addi tionally, after the temperature of the substrate has been enhanced, the grains of the coating become bigger, and the coating surface becomes more rough. An anti reflecting coating with good optical property must be a film formed by very fine grains. When it serves as a laser coating it must have a uniform and isotropic heat conductivity, therefore the structure formed by fine grians is necessary to enhance laser damage threshold. So it gives rise to inconsistency between the mechanical property and the optical property of the coating. This paper describes a new type of ZnS coating which has been deposited at low temperature, so it possesses fine grains and therefore its optical property is excellent. After annealing, the texture of the coating has been turned from pref érential orientation of (111) surface into that of (iiO),' at the same time, the coating possesses high strength and chemical stability, especially, its laser damage threshold is 1.9 times as high as that of the common one. This coating can be made either on monocrystal line substrate or glass substrate, with a coating area < 200 mm. In the last two years the authors have offered many ZnS coating with high optical properties and high strength as outside surface coating for the laser and thermal imaging systems
Surface and Interface
Study of photoelectric transformation process at p-PAn/n-Si interface
Renkuan Yuan,
Yu Xue Liu,
Hong Yuan,
et al.
Show abstract
Polyaniline (PAn) is a kind of stable semiconducting polymer. A p-n PAn/Si heterojunction has been prepared and the photoelectrical transformation process at the PAn/Si interface has been investigated. The factors affecting the photoelectrical characteristics of the PAn/Si heterojunction are discussed in this paper.
Organic and Polymer Films
Electrochromic property and chemical sensitivity of conducting polymer PAn film
Renkuan Yuan,
Zhi Ping Gu,
Hong Yuan,
et al.
Show abstract
The electrochromic property and chemical sensitivity of conducting polymer polyaniline (PAn) film prepared by electrochemical polymerization have been observed experimentally. The physical mechanism of color change of the PAn film has been discussed in light of the theories on the fundamental excitations in quasi-one dimensional conducting systems.
Film Formation and Analysis
Preferential growth in ion-beam-enhanced deposition of Ti(C,N) films
You Shan Chen,
Yi Lin Sun,
Fu Min Zhang,
et al.
Show abstract
As known to us, titanium nitride film formed by ion plating has been applied for decoration and hard coating in industry for years, but there still were many investigations on growing titanium nitride film by ion beam enhanced deposition in the past decade because of its benefit in cold processing and improved adhesion. There were also a few papers dealing with synthesis of titanium carbide by this technique. Ti(C,N) films are various solid solutions of titanium nitride and titanium carbide. They would incorporate the advantages of both and have attracted much attention. During a study of ion beam enhanced deposition of such films, a number of XRD patterns have been collected. This paper is a summary of these and its aim is to explain the formation mechanism in respect to orientation configuration of synthesized polycrystalline films. As various Ti(C,N) films have the same F.C.C. crystal structure of NaCl type as for TiN and TiC, the preferential orientations, which would be reflected in XRD, are only <111>, <100>, and <110> in spite of possible small peak shift due to composition change between that of TiC and TiN. We shall emphasize peak components and their relative intensity in the XRD patterns.
Superlattice Films
Molecular beam epitaxial growth of ZnSe-ZnS strained-layer superlattices
Ai Dong Shen,
Jie Cui,
Hai Long Wang,
et al.
Show abstract
High quality ZnSe-ZnS strained-layer superlattices (ELSs) were grown by molecular beam epitaxy (MBE). Photoluminescence and Raman-scattering measurements were carried out to evaluate the optical properties of the SLSs.
Raman spectra of ZnSe-ZnTe strained-layer superlattice
Show abstract
Various experimental and theoretical studies have been carried out on the phonon modes of III-V compounds semiconductor superlattices and II-VI SLS. Olego et al. have reported the confined LO modes in the ZnSe layer of the Zn-SeSxSe1-x SLS with resonant Raman scattering at low temperatures. Menendez et al. obtained the confined LOm modes in the CdTe-ZnTe SLS with the near resonance Raman scattering at 10 K. We report, for the first time, the confined LOm modes of the ZnSe-ZnTe SLS. The measurements were performed at room temperatures and under off-resonance conditions. There are a lot of studies on the strain in the SLS. Raman scattering provides a powerful techniques for the study of crystalline quality and especially strain fields of SLSs. By measuring phonon frequencies and their shifts, we can determine the strength of the strains in superlattice layers. In this paper, we report the strain effect on the phonon modes and the critical thickness of individual layers in ZnSe-ZnTe SLSs.
Films for Magnetic and Optical Recording
Organic-dye films for write-once optical storage
Jian Ping Zhou,
Juping Shu,
Huijun Xu
Show abstract
This paper describes a new type of organic dye-in-polymer films with phthalocyanine as the organic dye, which can be produced by spin-coating process. Differential thermal analysis has been performed in order to investigate into the homogeneity of the films. Two-layer type films, i.e., one recording layer coated over a reflective layer on a glass substrate, have been examined, and excellent stability as well as read-write characteristics were found satisfactory for practical use.
Film Formation and Analysis
Electrical resistance-strain characteristics and structure of amorphous Ni-Si-B thin films
Xian-an Cheng,
Qi Hua Gu,
Bing-yu Chen
Show abstract
The strain coefficient y and temperature coefficient of electrical resistance (TCR) and resistance stability of amorphous alloy Ni-Si-B films have been measured. These characteristics are related to the thickness of the film. The structure of the films have been examined by electron microscope. The results are discussed on the basis of microscopic columnar structure model of amorphous thin film and the Meiksin's Theory for effect of elastic strain on the electrical resistance of thin metal film.
Superlattice Films
Optical and electrical properties of Al-Al2O3-Cu tunnel junctions
Q. Q. Shu,
X. M. Tian,
X. Y. Chen,
et al.
Show abstract
Compared with Al-Al2O3-Au tunnel junctions, light emission output and I-V characteristics of Al-Al2O3-Cu tunnel junctions have been studied. The junctions with Cu films of 500 angstrom can be biased up to 2.9 eV at room temperature, and the light emission efficiencies were in the 10-6 range. The I-V curves have been measured at 77 K. Based on the dispersion curves of surface plasmon polariton at the interfaces and the barrier parameters of the junctions, a discussion of the results is given.
Ferroelectric and Dielectric Films
Growth mechanism of orientated PLZT thin films sputtered on glass substrate
Rui Tao Zhang,
Ming Ge,
Weigen Luo
Show abstract
Closely packed polycrystalline transparent PLZT(28/0/100) thin films with excellent crystal orientation have been successfully prepared on glass substrate by rf planar magnetron sputtering using powder target. The preferred orientation of PLZT(28/0/100) thin film is (100). Its growth mechanism can be described by Volmer-Weber Mechanism. At the incipience of sputtering, preferred orientated PLZT small islands are formed on glass. Then through the coalescence of these islands and recrystallization process, the polycrystalline orientated PLZT thin film is formed. In proper sputtering conditions, PLZT thin films with single orientation can be prepared.
Organic and Polymer Films
Corona charged polychlorotrifluorotylene film electrets, and its charge storage and transport
Zhong Fu Xia,
Jian Jiang
Show abstract
In this paper, the electret properties of negative and positive charging at room and elevated temperatures for polychlorotrifluorothylene (Aclar PCTFE) were studied by means of corona charging, electron beam bombardment, and thermally stimulated discharge (TSD). The shift of mean charge depth with the prolongation of time during aging at 150 degree(s)C after corona charging at RT was investigated. The transport model of detrapped charge in an Aclar PCTFE sample was discussed by means of laser induced pressure pulse (LIPP) method. The geometric distribution of traps with different activation energies along thickness was studied by means of electron beam discharge and TSD currents in combination with heat pulse method. At the same time, the comparison of the charge storage ability between positive and negative corona charged sample was carried out.
Superconducting Films
Bi(Pb)-Sr-Ca-Cu-O superconducting films prepared by chemical spray deposition
Changjiang Li,
Li Min Liu,
Qi Yao
Show abstract
A chemical spray deposition process (CSD) with nitrate acidic aqueous solution system as starting solution was developed to prepare Bi(Pb)-Sr-Ca-Cu-O superconducting films to high- alumina ceramic substrate. The films possessing superconducting transition with onset above 98 K and the zero-resistance state at 74 K were successfully obtained. By comparing CSD and bulk samples on structure, resistivity, morphology, and Raman spectrum, we conclude that the reaction between film and substrate was the major cause for low Tc.
Semiconducting Films
Ohmic and Schottky contacts to GaSb
Show abstract
The ohmic contact properties of Ag/AuGeNi/n-GaSb and AuGeNi/n-GaSb systems were investigated in this paper by measuring the barrier height and specific contact resistance with various sintering temperatures. The lowest specific contact resistance was about 8 X 10-3 - 8 X 10-4 cm2 for the Ag/AuGeNi/n-GaSb contact system when the sintering temperature was 400 degree(s)C for 2 min. Rutherford backscattering spectroscopy (RBS) was also used to study the interface between Ag/AuGeNi and GaSb during heat treatment. Pd/n-GaSb Schottky contacts have been studied experimentally before and after temperature annealing. I-V characteristics, Auger electron spectroscopy (AES), RBS, and x- ray diffraction patterns were used to determine and identify electrical performance of Pd/n- GaSb Schottky diodes. When the annealing temperature is increased to 450 degree(s)C, the rectifying property becomes bad. In this case, Pd interdiffusion and Ga, Sb out-diffusion to form Ga5Pd compound is very serious.
Ferroelectric and Dielectric Films
Study on different proportion W-Ti (C) binary alloy carbide thin film
Yun Han Zhang,
Bei Xin Wu,
Guang Yao Yang,
et al.
Show abstract
The authors have prepared different proportion W-Ti (C) binary alloy carbide coating by means of magnetron sputtering. In order to prove the performance of this superhardness binary alloy carbide coating, different performance tests have been carried out, such as tests for the structure and microhardness of the coating, and proportion of W and Ti in the coating, in particular, the effect of different W and Ti content on the hardness of the coating has been observed.
Film Formation and Analysis
Investigation of Ti-Al-Mo-V alloy nitride coatings by ARC technique
Ren Wang,
Guang Yao Yang,
Bei Xin Wu,
et al.
Show abstract
This paper introduces Ti-Al-Mo-V alloy nitride films grown on cemented carbide substrates using arc technique. Very hard, dense, and relatively smooth films, about 3 micrometers in thickness were obtained at aluminum content 20 - 30 at%. Such films exhibit high hardness value of over 4000 Hv 0.05 and better adhesion strength (critical load exceed 6 kgf) on cemented carbide substrates. The aluminum content in the films varies with the change of voltage of the substrates. All films were found, based upon x-ray diffraction, to be mainly (Ti, Al, Mo, V) N type compound nitride with (111) preferred orientation.
Surface and Interface
Investigation of defects in HgCdTe epi-films grown from Te solutions
Yue Wang,
Zhi Jie Tang,
Wei Sha Zhuang,
et al.
Show abstract
The defects on MCT epi-films grown from Te Solutions using liquid phase epitaxy method have been investigated by Metaloscope, x-ray diffraction meter, and electronic scanning microscopes. The observation results show that the defects in MCT epi-films, such as dislocation, twin, sub-grain, and boundary, have damaged the crystal-film's lattice structure and led to poor crystal perfection; the stress existed in the film has caused the lattice to deform and further widened the double crystal rocking curve of the film. It has been found that these defects in the MCT films are almost corresponding to that of CdTe substrates; LPE growth procedure and condition can also affect the quality of MCT films.
Infrared and Optoelectronic Films
Establishment of new criterion aiding the control of antireflection coating semiconductor diodes
Yu Cun Lu,
Da Yi Li,
Jianguo Chen,
et al.
Show abstract
The process of antireflector (AR) coating semiconductor diodes has been studied by employing the traveling-wave rate equations. As a result, a new criterion aiding the control of AR film deposition has been established. The agreement between theoretical predictions and experimental results is good.
Ferroelectric and Dielectric Films
Sol-gel derived BaTiO3 thin films
Show abstract
The challenge in making films specifically for optical devices lies in obtaining transparent films with sufficient crystallization and preferential orientation of the crystallites with respect to the substrates. Transparent BaTiO3, thin films have been prepared by the sol-gel process in our laboratory. The precursors were barium isopropoxide, titanium tetrabutoxide with isopropanol as solvent, and glacial acetic acid and acetylacetone as catalysts. By firing, transitions from amorphous to polycrystalline of the films took place in the temperature range of 600 - 650 degree(s)C. In order to obtain crack-free, more condensed films with preferential orientation and good electro-optic properties, strontium titanate single crystal (100) substrate is recommended.
Superconducting Films
Tensor resistivity and tensor susceptibility of oriented high-Tc superconducting film YBaCuO
Bi Hui Hou,
Zhen Zhong Qi
Show abstract
Abstract not available.
Preparation of superconducting Y-Ba-Cu-O thin films by rf magnetron sputtering
Zong Tan Huang,
Guozhen Li,
Guangli Zeng,
et al.
Show abstract
Since the discovery of high Tc superconducting oxides, including YBa2Cu3Ox, thin films of these material have been paid much attention due to their application potential in electronic devices. Several techniques have been employed to prepare superconducting thin films. Among them, sputtering technique using a single oxide target is one of the simplest and most useful methods. For our purpose, which is using superconducting thin films in some electronic devices, sputtering technique is presumably the best method for the deposition of thin films because of its controllability of film thickness, surface smoothness, homogeneity in quality, and tight sticking to the substrate and other layers. In this work, the authors have attempted to deposit YBa2Cu3Ox superconducting thin films by rf magnetron sputtering technique and tried to use them in some electronic devices.
In-situ low-temperature and epitaxial growth of high-Tc superconducting films using oxygen-discharge-assisted laser ablation method
Show abstract
High Tc superconducting films with zero resistance temperature of 91 K and critical current density about 105 A/cm2 at 77 K have been reproductively fabricated using oxygen discharge plasma-assisted excimer laser ablation method. Scanning electron micrographs and x-ray diffraction patterns of the films showed that these kinds of in situ prepared films had excellent epitaxial quality with its C axis oriented perpendicular to the substrate surface.
Superlattice Films
Study of crystal structure of vacuum-evaporated Ag-Cu thin film
Da Ming Sun
Show abstract
An investigation was made on the crystal structure of vacuum-evaporated Ag-Cu thin film. It's found that the Ag-Cu thin film can produce an ordering Cu3Ag superlattice structure. In addition, some preliminary theoretical studies are presented concerning the experimental results.
Organic and Polymer Films
Investigation on the DLC films prepared by dual-ion-beam-sputtering deposition
Tianmin Wang,
Weijie Wang,
Guidng Liu,
et al.
Show abstract
The diamond-like carbon films were successfully deposited onto Si, glass, Mo and stainless steel substrate at temperature less than 50 degrees C by dual-ion beam sputtering deposition. The influences of the bombarding ion beam energy, the bombarding ion beam current density and the ratio of hydrogen to argon gas flow in bombarding ion source on the properties and structures of films were investigated. It showed that the deposited films are composed of SP3 bond and SP2 bond with bond angle disorder. Depending on processing parameters and substrate, the predominant phase would be amorphous carbon, micro-graphite crystals or micro-cubic diamond crystals. With the increase of the parameters described above, the electrical resistivity of the films and the relative transmittance vs. wavelength curves of deposited glasses in IR region (1.5-5.5 µm) have tendency to increase first and then to decrease. The resistivities of the films deposited on Si, Mo and stainless steel range from 107 to 1012 (omega)cm. While on glass substrate, the square electrical resistivity varies from 105 to 109 (omega)/(box), the refractive index ranges from 1.1 to 2.6. The films and substrate have good adhesion force and the values between films and Si, Mo substrate are about 8 - 14 Kg/mm2. Combining the experimental conditions, the obtained results were disucssed.
Surface and Interface
Formation of boron nitride and silicon nitride bilayer films by ion-beam-enhanced deposition
Yi Ping Feng,
Bing Yao Jiang,
Gen Qing Yang,
et al.
Show abstract
Bilayer thin films of boron nitride and silicon nitride were prepared by sequential electron beam evaporation of Si or B and simultaneous irradiation with nitrogen ions. The composition and structure of the films were investigated by AES and IR analysis.
Film Formation and Analysis
Photothermal displacement spectroscopy of optical coatings
Xing Su,
Zhengxiu Fan
Show abstract
Photothermal displacement optical beam deflection spectroscopy (PDS) applied to optical coatings is discussed in detail. Theoretical analysis and results of numerical calculation are given, particularly in the interpretation of PDS signals. Primary aspects of its application are also presented.
Novel cathodic arc plasma PVD system with column target for the deposition of TiN film and other metallic films
Weiyi Liu,
Yu Min Li,
Zhan Jun Cui,
et al.
Show abstract
A novel cathodic arc plasma physical vapor deposition (PVD) process with column target for the deposition of metals and alloys has been developed. Low voltage and high current power is applied between the column target and anode. With the special designed magnetic field, the arc spots run circularly on the surface on the column target and move up and down with the movement of the magnetic field. The erosion on the target is well distributed. The discharge process is very stable and the working conditions are very wide. The working gas can be argon, nitrogen, oxygen, or any other gases according to the need of the chemical reactive deposition.
Surface and Interface
Energy bands of graphite and CsC8-GIC, and CO physisorption on graphite basal surface
Yong Yang,
Jian Qing Guo,
Dong Lu
Show abstract
By using Wannier function constructed from a set of localized functions in a variational procedure, the energy bands of graphite were calculated. And the band structure of CsC8 graphite intercalation compound was calculated with use of the method developed by Ohno, Nakao, and Kamimura. It was found that the results of these calculations were in reasonable agreement with the various literatures. The CO molecule absorption on graphite basal surface was calculated by a cluster model and extended Hackel theory method. It indicated that the CO adsorbates might form a commensurate configuration.
Optical Films
Determination of optical constants of thin film in the soft x-ray region
Yong Hong Guo,
Zhengxiu Fan,
Ouyang Bin,
et al.
Show abstract
We presented a method of determining optical constants of a thin film using the reflectance R(theta) curve. Other parameters of the film, such as film thickness and roughness, are also determined with the derivation of the optical constants(n,k). To illustrate the method, the results of the film Al are given.
Thermal process of laser-induced damage in optical thin films
Zhengxiu Fan,
Zuo Liang Wu,
Zeng Rong Shi
Show abstract
Thermal process of optical thin film irradiated by laser is a fundamental process for laser induced damage. The energy deposition in thin film is induced with built absorption, defect absorption, multi-photon absorption, or avalanche ionization in thin film. Thus, the temperature is increased in the absorption site and a heat source is formed. The heat is transferred to another region through heat conduction. The interaction process of laser and thin film is very complex. This film is breakdown when the temperature is raised to a definite value. Thermal process of optical materials was researched by some authors. But detailed research about the thermal process of multilayers was very few. Presented in this paper are the theoretical formula and calculation results of temperature distribution in multilayer. In situ process of interaction between laser and thin films was monitored by photothermal deflection technique. The theoretical analyses are consistent with the experimental results.
Organic and Polymer Films
Temperature dependence of resistance of diamond film synthesized by microwave plasma CVD
Bangchao Yang,
Li Gou,
Yu Ming Jia,
et al.
Show abstract
Diamond has many excellent properties, such as the greatest hardness (10000 kg/mm2), high thermal conductivity (5 times that of Copper at 20 degree(s)C), wide energy gap (5.5 eV), good chemical stability, etc. But for a long time, the shape and the high cost of diamond made by high-pressure, high-temperature method severely limit the application of the diamond in electronics and optics. Since the diamond film was synthesized, people began to study further the properties of the diamond film. It is expected to be a new kind of function material. This is a report of the temperature dependence of the resistance of the diamond film. The authors also attempted to prepare the thermistor made of polycrystal diamond film on silicon substrate.
Film Formation and Analysis
Research on influence of substrate to crystal growth by ion beams
Show abstract
The change of grain size and structure in several metal films on different substrate by Ar+ bombarding has been shown. The experimental results show that the size of film grain will become bigger and even form single crystal under special bombarding conditions. It is also found that some factors of substrate, such as lattice structure, lattice parameter, and deposited surface, etc., have a great influence upon its growth. A new mechanism of crystal growth has been investigated.
Optical properties of oxide films prepared by ion-beam-sputter deposition
Show abstract
TiO2 and ZrO2 coatings were prepared by ion beam sputter deposition. Refractive indices, optical absorptions, and laser-induced damage thresholds of the films were investigated. The optical absorptions of thin films are decreased obviously.
Ta/Al alloy thin film medium-power attenuator
Bangchao Yang,
Yu Ming Jia
Show abstract
Ta/Al alloy resistive thin film has become more and more attractive in manufacture of the high-accurate and high-stable thin-film power resistance and its network due to its excellent thermal stability since the 1970s. In this paper, both Ta/Al alloy resistive film containing Al 50 at.% and the medium-power thin-film attenuator used for microwave circuit are studied and analyzed.
Semiconducting Films
Research on relaxation process of a-Si:H film photoconductivity and the trap effect
Dao Ben Gong
Show abstract
By using monochromatic light from the monochromator and super-resistance measurement instrument and function recorder, we measured the relaxation phenomena of the a-Si:H film photoconductivity and obtained some regularities. We propose that the relaxation time ((tau) ) according to exponential changes is mainly affected by minority carrier traps and the effect of majority carrier traps makes the photoconductivity relaxation process deviate from the exponential curve and greatly delays the actual relaxation time. We have not found so far any paper dealing with the different effects of these two types of traps.
Film Formation and Analysis
Superconducting Films
Ion-beam-sputtering deposition and etching of high-Tc YBCO superconducting thin films
Xing-Rong Zhao,
Jianhua Hao,
Fang Qiao Zhou,
et al.
Show abstract
High Tc YBaCuO superconducting films have been prepared with ceramic and powder targets, the typical deposition parameters have been given. We also patterned YBCO films with a parallel Ar ion source. Little degradation of Tco by the etching was observed.
Films for Magnetic and Optical Recording
(Sb2Se3)1-x Nix alloy thin films and its application in erasable phase change optical recording
Show abstract
Reported here are the experimental results about Ni-doped Sb2Se3 phase change recording thin films prepared by DC & RF magnetron co-sputtering. It is found that doping a small percentage of nickel (Ni) into Sb2Se3 thin films have the effect to increase the films recording sensitivity and decrease the polycrystalline grain size about one order of magnitude after 8.9 at% of Ni is doped. The sample's static test for erasable optical recording shows that using 20 mW, 200 ns, or 15 mW, 200 ns laser pulses, a recoding bit can be written or erased on the film, thus Ni-doped Sb2Se3 media have the potential for practical rewritable recording.
Optical Films
Soft X-UV silver silicon multilayer mirrors
Show abstract
In the soft x-ray domain (near 10 nm), the reported optical constants of silver and silicon are sufficiently different to make them attractive for a multilayer design. In this paper, design and fabrication of silver/silicon multilayer to be used as normal-incidence reflectors for 11.4 nm radiation are presented. Characterization of these multilayer structures was accomplished using Auger electron spectroscopy (AES) and little-angle x-ray diffraction (LXD). As a result of our experiments, we came to realize that silver/silicon multilayer can provide high quality structures and reach a certain reflectance.
New approach to obtain uniform thickness ZnS thin film interference filters
Yuan Sheng Mei,
Shi-Xuan Shang,
Jin An Shan,
et al.
Show abstract
In very large-scale integrated circuits, the switch of semiconductor elements has a very fast speed, but the information transfer speed is lower than that of the switch, thus deterring the whole computing speed. For optical elements, the ability to solve the problem is evident. This is supported by several facts: high switch and transfer speed and independent transfer of optical information. Using ZnS, Na3AlF6 interference filter as optical switch elements, the uniform thickness of thin film is essential to the optical parallel processing. The theoretic model for vacuum vapor thin film thickness distribution has been given with some assumptions. In view of the practical vapor condition and the vapor material, some modification is needed. By using an addendum as a limit to allow only some molecules to reach the surface of substrate, a uniform thickness thin film can then be obtained.
Organic and Polymer Films
Amorphous microcellular polytetrafluoroethylene foam film
Chongzheng Tang
Show abstract
We report herein the preparation of novel low-density ultramicrocellular fluorocarbon foams and their application. These fluorocarbon foams are of interest for the biochemistry arena in numerous applications including foodstuff, pharmacy, wine making, beer brewery, fermentation medical laboratory, and other processing factories. All of those require good quality processing programs in which, after eliminating bacterium and virus, compressed air is needed. Ordinarily, compressed air contains bacterium and virus, its size is 0.01 - 2 micrometers fluorocarbon foam films. Having average porous diameter 0.04 - 0.1 micrometers , these are stable to high temperature (280 degree(s)C) and chemical environments, and generally have good engineering and mechanical properties (e.g., low coefficient of thermal expansion, high modulus, and good dimensional stability). Our new process for preparing low density fluorocarbon foams provides materials with unique properties. As such, they offer the possibility for being superior to earlier materials for a number of the filter applications mentioned.
Film Formation and Analysis
Experimental study of microwave attenuation of ITO-dielectric recombination film
Guang Lian Huang,
Jun Zhang,
ChangQing Peng
Show abstract
In this paper, the properties of microwave attenuation of ITO-dielectric recombination film are studied by means of experiment. Some curves of attenuation with square resistance and frequency are given when electromagnetic wave transmits through the thin film. The discussion covers ITO-dielectric recombination film. UV spectacles coated with ITO is compared to UV spectacles coated with ITO-MgF2 recombination film. The characteristics of the recombination film are good. These analyses form the base for industrial use of the recombination films.
Ferroelectric and Dielectric Films
Research of Cr2O3 thin film deposited by arc discharge plasma deposition as heat-radiation absorbent in electric vacuum devices
Hong Deng,
Xiang Dong Wang,
Lei Yuan
Show abstract
Formation of chrome oxide thin film on an iron substrate by arc discharge plasma as a heat- radiation absorbent in electric vacuum devices is described. Only oxygen as reaction gas without argon is applied in the discharge chamber and an improved film with good properties is obtained.
Film Formation and Analysis
Thermal stability and microstructure study of WSi0.6/GaAs by XRD and TEM
Shu Yuan Zhang,
Shun Tan,
Changsui Wang,
et al.
Show abstract
WSix/GaAs is a kind of Schottky gate material which has been successfully applied to prepare various electrical devices. In literature there are reports about electrical properties and thermal stabilities of WSix/GaAs systems. But the results on thermal stability were not coincidence. So far we have not found an article about the WSix/GaAs system investigated by transmission electron microscopy (TEM). The TEM cross-section is the best way to reveal the microstructures of WSix/GaAs system at various annealing conditions. In this work the WSi0.6/GaAs system has been investigated by x-ray diffraction (XRD) and TEM. Some valuable results have been obtained.
Semiconducting Films
Crystallization of hydrogenated amorphous silicon film and its fractal structure
Hongyi Lin,
Daoming Yang,
Ying Xue Li
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Morphology of fractal structure in hydrogenated amorphous silicon (a-Si:H) films at different annealing temperatures is observed using transmission electron microscope (TEM). The experimental method is an in situ dynamic observation technique. The fractal dimensions are calculated with the Sandbox method. With the annealing temperature at 450 degree(s)C, the fingering-like fractal structures are grown in the films and the fractal dimension is 1.69. At 800 degree(s)C, the fractal dimension is 1.76. The experimental results show the fractal structures in a-Si:H films. The relationship between the fractal structures in a-Si:H films and its crystallization are discussed.
Superconducting Films
In-situ laser preparation of high-Tc superconducting thin film at 450-550 degree C
Show abstract
Superconducting thin films of Y-Ba-Cu-O on zirconia substrate are prepared using excimer laser (308 nm, 28 ns) ablation of a superconducting Y-Ba-Cu oxide disk without plasma assistance in the substrate temperature range from 450 - 550 degree(s)C. The high or low- temperature post-annealing in an oxygen atmosphere is not necessary. The highest zero resistance temperature of the produced film is up to 91.5 K. X-ray diffraction spectra reveal that the thin films are preferential x-axis orientation normal to the surface. The key to the success is increasing the oxygen pressure in the deposition chamber to about 220 mTorr and making the ejected oxygen interact with the laser beam before it comes to the deposition area. The influences of the oxygen pressure ejected into the chamber, of the laser flux density and of the substrate temperature on the superconducting property of the produced thin films are discussed.
Superlattice Films
Optical emission spectroscopy in diamond-like carbon film deposition by glow discharge
Show abstract
We have measured the optical emission spectra of glow discharge plasma of methane in the diamond-like carbon film deposition and analyzed the relationship between the optical emission spectra and deposition parameters, such as rf power and gas pressure. The infrared absorption of films has also been measured and compared with the results of optical emission spectra measurements.
Optical Films
Multiple-pulse laser damage to thin film optical coating
Zhong Ya Li,
Cheng Fu Li,
Ju Ping Guo
Show abstract
In this paper, accumulation effects of multiple pulse laser-induced damage to thin-film optical coating at 1.06 micrometers and 0.53 micrometers are reported. The relationship between damage probability and laser energy and pulse repetition frequency are investigated.
Films for Magnetic and Optical Recording
Laser-induced phase transition in crystal InSb films as used in optical storage
Yang Sun,
Cheng Fu Li,
He Deng,
et al.
Show abstract
We have analyzed the transient phase transition process in c-InSb films by the measurement of temporal reflectivity change. The results show that InSb film is a promising medium for optical storage, and the reflectivity change measurement is a useful method to explore the dynamic processes in thin films and the material's surfaces under pulsed laser irradiation.
Advanced thin films for optical storage
Show abstract
In this paper, the mechanism, optical, and recording properties of rare-earth-transition metal alloy films for magneto-optical data storage, the writing and erasing characteristics of InSb- and GeTe-based alloy films for phase change type, and organic materials for photo-gated persistent spectral hole burning and photochromic recording are reviewed. In addition, several specific theoretical and experimental results in such fields are given.
Film Formation and Analysis
Structure of very thin metal film
Yongjie Huang,
Ping Jiang
Show abstract
The modified point-ion model has been successfully used to calculated multilayer relaxation on metal surfaces. This model uses a single parameter (alpha) to simulate the unhomogeneous electron density distribution in a semi-infinite metal although its value should fit experimental data for a given material. This model was only used to calculate the semi-infinite metal before, however, it could be applicable for calculating the structure of the thin film consisting of very few atomic layers. As far as our knowledge goes, neither theoretical nor experimental data has been reported in this respect. In this paper, we use this model to calculate preliminarily the thin film structure of some fcc and bcc surfaces.
Films for Magnetic and Optical Recording
Fractal simulation of aggregation in magnetic thin film
Yi Ping Wang,
Yu Jin Wang
Show abstract
According to the real experimental processes to be induced at the solid thin film by ion irradiation, we set up a hybrid model of fractal aggregation which is different from Brownian motion model (DLA, CDA, and RLCA), rectilinear trajectory model, and molecular dynamics model (MD). The results of simulating coincide with those of the experiments.
Film Formation and Analysis
Structure and optical properties of a-C:H/a-SiOx:H multilayer thin films
Wei Ping Zhang,
Jing Bao Cui,
Shan Xie,
et al.
Show abstract
Amorphous multilayer thin film a-C:H/a-Si:H was deposited by magnetron sputtering. X-ray diffraction and Auger electron spectroscopy measurements indicate very well the periodicity of the sample. The shift and broadening of the photoluminescence peak are interpreted in light of quantum size effect.
Study of phase transition VO2 thin film
Jiancun Gao,
Zhi Hong Lin,
Liying Han
Show abstract
Vanadium dioxide thin film that has semiconductor-to-metal phase transition has been obtained by either reactive evaporation or reactive ion assisted deposition with subsequent annealing processes. Various kinds of measurement methods have been developed in investigation of phase transition properties of vanadium dioxide films. It is observed that the performance of phase transition properties strongly depends upon the stoichiometric and crystalline characteristics of the thin film.
Interaction between the excitons and electrons in ZnSe1-xSx epilayer under high excitation
Show abstract
Excitonic properties of ZnSe1-xSx epilayer fabricated on GaAs substrate by a Ap-MOCVD have been investigated. Luminescence, excitation, and time-resolved spectroscopy have been employed to study the interaction between excitons and electrons at 77 and 300 K. Under pulsed N2 laser excitation it is found that the peak shift of the near band edge emission is large, especially at room temperature. This is because the bottoms of the conduction bands are filled at higher temperature and the carriers from the exciton-exciton scattering must occupy higher energy levels. Therefore a shift of the peak toward lower energy is expected.
Ferroelectric and Dielectric Films
Preparation of PbTiO3 thin film by dc single-target magnetron sputtering
Bangchao Yang,
Ju Yong Wang,
Yu Ming Jia,
et al.
Show abstract
This paper describes the preparation of PbTiO3 thin film by DC single-target magnetron reactive sputtering, which hasn't yet been reported. After many experiments, the best Pb/Te area ratio of the target has been found under a specified sputtering condition. The samples obtained are heat-treated to 600 degree(s)C and the x-ray diffraction patterns are observed. The authors have succeeded in preparing almost transparent and light yellow perovskite-type PbTiO3 with resistivity of 107(Omega) cm.
Film Formation and Analysis
Microstructure of titanium oxide thin films
Rui-Ying Fan,
Yue Mei Lu,
Xiangyun Song
Show abstract
Reported here are the TEM studies about the microstructures of TiO2 and Ti3O5 thin films thermally annealed at different temperatures and the microstructure change of TiO2 thin films before and after the laser-induced damage. Cross sectional TEM images of IAD deposited TiO2 singlelayer and TiO2/SiO2 multilayers are also observed and analyzed.
Films for Magnetic and Optical Recording
Thin film magnetic recording
Show abstract
Magnetic recording now dominates the data, video, and audio storage for both professional and consumer applications. The technology has improved immensely as understanding of the physics of recording and reproducing processes is gained. Advances in recording materials and processes for fabricating components, especially with the thin film media and heads, have contributed in a major way to extending the performance of magnetic recording technology into different industries. Some examples of magnetic thin films applicating for recording media and heads studied in Information Storage Research Centre of Shanghai Jiao Tong University are described.
Infrared and Optoelectronic Films
Optical nonlinearities of ZnSe thin films
Show abstract
We have measured the nonlinear absorption change in ZnSe thin films at 77 K. The nonlinear mechanisms are attributed to the combination of the increasing absorption and the bleaching of excitons.
Superconducting Films
Luminescence studies in the process of preparation high-Tc superconducting films with excimer laser ablation
Show abstract
The luminescence spectra of the ejected particles from laser ablation of the superconductor was measured with the optical spectrum analyzer. In the experiment, the Y-Ba-Cu-O superconductor was adopted as target. When it was bombarded with excimer laser pulse, the target materials evaporated and luminescence plasma plume was formed above the target surface. By identifying the emission spectrum lines, the types and excited states of the ejected particles was determined. Meanwhile, the characteristics of the velocity distribution and luminescence intensity distribution of the ejected particles were studied by time- and space- resolved spectroscopic techniques.
Infrared and Optoelectronic Films
Application of YBa2Cu3O7-x thin film in high-Tc semiconducting infrared detector
Bing Zhou,
Ju Xin Chen,
Bao'an Shi,
et al.
Show abstract
The discovery of high transition temperature superconductors was soon followed by the recognition of their potential important as superconducting transition-edge bolometers. The properties of applied YBaCuO thin film, such as width of superconductor-transition range, dominates the sensitivity of bolometers. The properties partially depend on the substrates. There are some recent papers in this field. We have fabricated high Tc superconducting infrared bolometer using two types of substrates, (100) SrTiO3 and (100) LaAlO3, with the same size of 10 X 3 X 0.3 mm3. We have tested and compared the two kinds of bolometers.
Surface and Interface
ZnS:Mn thin film electroluminescent display devices using hafnium dioxide as insulating layer
C. T. Hsu,
Jiin Wen Li,
C. S. Liu,
et al.
Show abstract
The ac thin film EL possesses the properties of high resolution, compact, high brightness, and large area, etc. One of the important subjects is the choice of dielectric materials for use in ACTFEL displays. In this paper we discuss the electrical and optical performances of EL devices with BaTiO3, Ta2O5, Al2O3, and HfO2 as insulating layers. From the results, we find that EL devices with a glass/ITO/BaTiO3/ZnS:Mn/HfO2/Ta2O5/HfO2/Al structure are excellent in brightness and efficiency.
Optical Films
New definition of laser damage threshold of thin film: optical breakdown threshold
Xiao-Wu Ni,
Jian Lu,
Anzhi He,
et al.
Show abstract
The mechanism of laser-induced damage to thin films is described in this paper, and a definition of laser breakdown threshold to thin film, optical breakdown threshold is presented. The new definition is clearer than the existing one. The measurement results and comparison for various samples are given on the basis of the two above-mentioned definitions.
Film Formation and Analysis
Organo-metallic thin films for erasable photochromatic laser discs
Zhongyi Hua,
G. R. Chen,
Z. H. Wang
Show abstract
A new category of erasable optical storage media, M1-(Beta) (TCNQ) films, is described. The photochromatic effect of thin organometallic charge-transfer complex can give high contrast patterns directly produced on the film by pulsed photon beams generated from a He-Ne tube or a semiconductor laser. The patterns are erasable by the same light source under different irradiating conditions. Typical experimental results were as follows: For (lambda) equals 632.8 nm, write-in power equals 16 mW, pulse duration equals 300 ns; erasing power equals 8 mW, pulse duration equals 25 microsecond(s) ; coefficient of contrast K > 50%; number of write- erase cycles N > 1000. For (lambda) equals 830.0 nm, write-in power equals 12 mW, pulse duration equals 650 ns; erasing power equals 4 mW, pulse duration equals 15 microsecond(s) ; K > 25%; N > 120.
Semiconducting Films
Charge characteristics of thin rapid-thermal-nitrided SiOxNy film in MIS structure
P. Sheng Chen,
Jing Yang
Show abstract
This paper studies the charge characteristics and the interface trapping of new-type thin rapid thermal nitrided SiOxNy film (RTNF) and thin reoxidized nitrided SiOxNy film by the photo I-V method and the avalanche hot-electron injection technique. The research results give the bulk charge density and its distribution centroid position of thin RTNF and thin conventional SiO2 film. The reoxidation processing after rapid thermal nitridation reduced effectively the densities of bulk electron trapping and interface state in the RTNF. A physical model explanation of weakly-present 'N' form change for flatband voltage shift with avalanche injection dose also was presented. The change relationship of energy distribution for interface state density with injection dose was obtained. The theoretical analyses and discussions of these research results are included in this paper.
Superconducting Films
Preparation and O+ implantation of Y-Ba-Cu-O superconducting thin films by sputtering and RTA process
Xiang Jun Fan,
Huai Xi Guo,
Chang Zhong Jiang,
et al.
Show abstract
An ion beam sputtering and a magnetron sputtering technique was respectively employed to deposit Y1B2aCu3O7 thin films. After deposition, the films were annealed by three-step rapid thermal annealing (RTA) in flowing oxygen. The zero resistance temperature of the superconducting thin films were achieved above 80 K. X-ray diffraction shows that the sputtered films have a c-axis orientation perpendicular to the film surface like epitaxial film. It is found that the proportion of yttrium was higher than the composition of the thin film within 60A from the surface measured by XPS. The EPMA shows that the proportion of yttrium was considerably decreased by the annealing procedure. 120 Kev O+ has been implanted into Y-Ba-Cu-O as-deposited films. The initial values of resistance were strongly reduced with increasing Oo doses. The resistance vs. temperature curves of implanted films are characterized as a semiconductor with a negative temperature coefficient.
Ferroelectric and Dielectric Films
X-ray evaluation on residual stresses in vapor-deposited hard coatings
Kewei Xu,
Jin Chen,
Runsheng Gao,
et al.
Show abstract
Residual stresses in plasma assisted vapor deposited (PECVD) TiN coatings were evaluated with x-ray diffraction method. They are tensile on substrate of cemented carbide, but compressive on that of steel. The magnitude is between those made by chemical vapor deposition (CVD) and physical vapor deposition (PVD). The residual stresses display different values on a substrate of steel or cemented carbide, yet no distinct change on substrates of various kinds of steels or of cemented carbides. As the depositing temperature increases, both the macro and the micro residual stress represented by the relative displacement and the broadening of diffraction profile decrease. This implies that the stresses produced by PECVD in normally lower temperature are dominated mainly by the constituents and microstructural aspects of the coating material rather than by different thermal expansions between the coating and the substrate.
Infrared and Optoelectronic Films
ZnS/Me heat mirror systems
Xiao Ping Zhang,
Shan-qing Yu,
Min Wei Ma
Show abstract
The spectral selective transmission and heat conservation efficiency of some heat mirror systems consisting of ZnS/Me (Me equals Al or Ag) under a different configuration have been studied. It is shown that the 15nmZnS/20nmAg system has optimistic spectral selective transmission in visible wavelength range and the highest reflection in infrared wavelength range. Ag can keep its optical characteristic after heating to 200 degree(s)C by the protecting thick layer of ZnS. The system consisting of 15nmZnS/10nmAl is the efficiency heat mirror in the ZnS/Al systems. It is a cheaper material in application although it cannot compare with ZnS/Ag systems.
Superconducting Films
Superconductivity and structural changes of Ar ion-implanted YBa2Cu3O7-x thin films
Yi Jie Li,
Cong Xin Ren,
Guo Liang Chen,
et al.
Show abstract
The effects of Ar ion implantation on superconductivity and structural changes in epitaxial YBa2Cu3O7-x thin films have been studied using x-ray diffraction, scattering electron microscopy (SEM), and transmission electron microscopy (TEM). It was found that both the critical current density Jc and the superconducting transition temperature Tc significantly decreased with the fluence. The sample went through the metal to semiconductor to insulator transitions with the increase of fluence. The TEM images showed that the sample implanted with high fluence became amorphous.
Film Formation and Analysis
SPAT studies of near-surface defects in silicon induced by BF2+ and F++B+ implantation
Xiao Qin Li,
Chenglu Lin,
Shichang Zou,
et al.
Show abstract
Slow-position annihilation technique (SPAT) has been made on silicon samples implanted with BF2+ and F+ + B+ to study the irradiation defects in the thin surface layer (approximately 700 angstrom). The Doppler broadening of the annihilation (delta) -ray energy spectra measured at a number of different incident-positron energies (0 - 16 keV) was characterized by line-shape parameters 'S.' The difference between the S parameter for implanted silicon and that for unimplanted silicon provided information about the concentration and depth of the defects. The results are identical with that obtained from high resolution Rutherford backscattering and channeling technique. This investigation demonstrates that SPAT is a powerful and sensitive technique for measuring the defects distribution in semiconductors.