The ability to model the effect of fields due to charges trapped in insulators with floating conductors has been added to JMONSEL (Java Monte Carlo simulator for Secondary Electrons) and applied to a simple photomask metal on glass geometry. These capabilities are prerequisites if model-based scanning electron microscope (SEM) metrology is to be extended beyond wafer to photomask applications, where such samples must frequently be measured. Model-based SEM is an alternative to the customary threshold- or gradient-based approach. It is more demanding inasmuch as it requires a model of the physics of image formation, but the reward is greater accuracy, lower sensitivity to secondary sample characteristics (e.g., edge shape) that affect the intensity, and information about 3D geometrical shape (not simply the width) of the measured features. The prerequisites are ability to measure a signal, such as the SEM image, that is sensitive to changes in the parameters one wishes to measure and a model that describes the relationship between the signal and the parameters. The simulation shows the development of the potential energy barrier to electron escape during an initial transient charging-up phase, accompanied by increasing electron recapture and stabilization of the average yield.

Atmospheric scanning electron microscopy (ASEM) for observing samples at ambient atmospheric pressure is introduced in this study. An additional specimen chamber with a thin membrane allowing electron beam propagation is inserted in the main specimen chamber. Close proximity of the sample to the membrane enables the detection of backscattered electrons (BSEs) sufficient for imaging. A probability analysis of the un-scattered fraction of the incident electron beam and the beam profile further supports the feasibility of atmospheric SEM imaging over a controlled membrane-sample distance. An image enhancement method based on the analysis is introduced for the ASEM.

This is the third of a series of papers discussing various causes of measurement uncertainty in scanned particle beam instruments, and some of the solutions researched and developed at NIST. Scanned particle beam instruments especially the scanning electron microscope (SEM) have gone through tremendous evolution to become indispensable tools for many and diverse scientifi c and industrial applications. These improvements have signifi cantly enhanced their performance and made them far easier to operate. But, ease of operation has also fostered operator complacency. In addition, the user-friendliness has reduced the need for extensive operator training. Unfortunately, this has led to the concept that the SEM is just another expensive digital camera or another peripheral device connected to a computer and that all of the issues related to obtaining quality data have been solved. Hence, a person (or company) using these instruments may be lulled into thinking that all of the potential pitfalls have been fully eliminated and they believe everything they see on the micrograph is always correct. But, as described in this and the earlier presentations this may not be the case. The fi rst paper in this series discussed some of the issues related to signal generation in the SEM, including instrument calibration, electron beam-sample interactions and the need for physics-based modelling to understand the actual image formation mechanisms to properly interpret SEM images. The second paper, discussed another major issue confronting the microscopist: specimen contamination and methods of contamination elimination. This third paper, discusses vibration and drift and some useful solutions.

In this work the characterization of CMOS diodes with Electron Beam Induced Current (EBIC) measurements in a Scanning Electron Microscope (SEM) are presented. Three-dimensional Technology Computer Aided Design (TCAD) simulations of the EBIC measurement were performed for the first time to help interpret the experimental results. The TCAD simulations provide direct access to the spatial distribution of physical quantities (like mobility, lifetime etc.) which are very difficult to obtain experimentally. For the calibration of the simulation to the experiments, special designs of vertical p-n diodes were fabricated. These structures were investigated with respect to doping concentration, beam energy, and biasing. A strong influence of the surface preparation on the measurements and the extracted diffusion lengths are shown.

We introduce a novel transmission electron imaging method to clarify the internal structure of single whole cells by scanning electron microscopy (SEM). In this method, whole cells are cultivated on a transparent flat plate in advance, which is made of a scintillator that emits photons by irradiating an electron beam. The detector developed here can obtain both the secondary electron (SE) surface images and transmission electron (TE) images. Observations of whole mount cells by this technique clearly show that the cellular internal structure can be observed as transmission images which are produced by photons emitted from the scintillator plate by electron beam irradiation.

This paper gives an overview of the possible methods for a three-dimensional surface acquisition in the micrometer scale. It is pointed out that Scanning Electron Microscopy is a capable method for measurement tasks of this kind; therefore, it presents possible ways for implementing this technique in a three-dimensional surface reconstruction. The improved photometric method promises the best performance; its further implementation is developed and explained. Therefore, some modifications of the employed Scanning Electron Microscope (SEM) are described, for instance, the integration of two supplemental detectors, a modified collector grid and a gun shielding. All modifications were evaluated using FEM-Simulations before their implementation. A signal mixing is introduced in order to still be able to use the improved photometric method with four detectors in spite of the fact that it was designed for a two-detector system. For verification purposes, a sphere normal is measured by means of the modified system. It can be seen that the maximal detectable slope angle could be increased compared to the old photometric method. In addition, we introduce an electron trap consisting of nano structured titanium. The structure is tested regarding its ability to catch electrons of different energies and compared to non-structured titanium. The trap can later be implemented on the bottom of the electron gun to catch unwanted backscattered electron (BSE) emission which could otherwise affect the three-dimensional reconstruction.

In this article we describe application of piezoresistive cantilevers in surface investigations carried out with the use of shear force microscopy (ShFM). The novel piezoresistive cantilevers integrate a Wheatstone piezoresistive bridge was used to detect the cantilever deflection, thermal deflection detector and planar tip protruding out of the spring beam. Because the planar tip deflection can be detected and controlled electronically the described technology is very flexible and can be applied in many surface investigations. In this article we will present operation theory of the described solution, experimental setup, methods for calibration of the tip deflection detection and actuation The analysis will be illustrated with example results of topography measurements performed using the described technology.

Conventional scanning electron microscopes are limited in their ultimate data acquisition rate at a given resolution by statistical electron-electron interaction (so-called Coulomb interaction) as well as band width of detectors and deflection systems. We increased imaging speed dramatically by using multiple electron beams in a single column and parallel detection of the secondary electrons. The multi-beam SEM generates multiple overlapping images during a single scan pass, thereby covering a larger area in shorter time as compared to a single-beam SEM at the same pixel size. This addresses the upcoming need for high speed imaging at electron microscopic resolution to investigate larger and larger areas and volumes.

Miniature columns or microcolumns are a relatively new class of electron beam columns fabricated entirely from silicon using advanced micromachining processes. The main characteristics of these columns are thermal field emission (TFE) sources, low voltage operation (typically <3keV), simple design (two lenses, no crossover), microfabricated lenses, and all electrostatic components. Current production versions of miniature columns achieve <10nm resolution at 1keV, and have demonstrated <6nm resolution at higher beam energies.^1,2 While this performance is suitable for most applications, previous studies of the electron optics of miniature electrostatic lenses show better performance should be attainable under “ideal” conditions.³ In practice, achieving these conditions is challenging because, in addition to the manufacturing errors from the miniature optics, other subsystems can impose additional constraints. An understanding of the major contributors to column performance, whether optical or mechanical, is essential, and can provide a roadmap for further improvements in the existing technology.

SEMATECH has initiated a program to accelerate the development and commercialization of multi-electron beam based technologies as successor for wafer defect inspection in high volume semiconductor manufacturing. This paper develops the basic electron-optical performance requirements and establishes criteria for tool specifications. The performance variations within a large array of electron beams must be minimal in order to maximize defect capture rates while simultaneously minimizing false counts, so a series of experimental evaluations are described to quantify the random and systematic variations in beam current, spot size, detector channel noise level, and defect sensitivity.

Quantitative electron-excited x-ray microanalysis by scanning electron microscopy/silicon drift detector energy dispersive x-ray spectrometry (SEM/SDD-EDS) is capable of achieving high accuracy and high precision equivalent to that of the high spectral resolution wavelength dispersive x-ray spectrometer even when severe peak interference occurs. The throughput of the SDD-EDS enables high count spectra to be measured that are stable in calibration and resolution (peak shape) across the full deadtime range. With this high spectral stability, multiple linear least squares peak fitting is successful for separating overlapping peaks and spectral background. Careful specimen preparation is necessary to remove topography on unknowns and standards. The standards-based matrix correction procedure embedded in the NIST DTSA-II software engine returns quantitative results supported by a complete error budget, including estimates of the uncertainties from measurement statistics and from the physical basis of the matrix corrections. NIST DTSA-II is available free for Java-platforms at: http://www.cstl.nist.gov/div837/837.02/epq/dtsa2/index.html).

The investigation of garment and human tissue originating from a victim of a shooting incident can provide crucial information for the reconstruction of such an incident. The use of 2D-mXRF for such investigations has several advantages over current methods as this new technique can be used to scan large areas, provides simultaneous information on multiple elements, can be applied under ambient conditions and is non-destructive. In this paper we report our experiences and challenges with the implementation of 2D-mXRF in GSR analysis. Currently we mainly focus on the use of 2D-mXRF as a tool for visualizing elemental distributions on various samples.

The Texas DPS Crime Laboratory Service analyzes an average of 45 gunshot residue (GSR) kits a month using three different SEM/EDS systems and involving four different analysts. To maintain the volume of cases, we have developed a robust, cost-efficient method to ensure that all three systems are performing automated GSR analysis within laboratory specifications, and yielding consistent results across all three systems. This analysis commonly includes analysis of GSR kits collected from suspects’ hands, but can also include kits from screening of suspects’ clothing for GSR. Analysts have developed procedures for cleaning and monitoring areas where clothing and GSR stubs are processed and analyzed in order to ensure that casework stubs were not contaminated in the laboratory.

An organic compound, originally marketed as an antistatic, can form an extremely thin electro-conductive coating upon drying. A scanning electron microscope (SEM) application for this compound was first explored in the late 1960s. A coating of this compound eliminates the need for carbon or gold coating in some applications. It is well suited for the viewing of fabric samples and associated gunshot residue (GSR) in the SEM and makes it possible to quickly analyze fabric bullet wipe and bore wipe GSR. Fabric samples can also be examined for GSR from intermediate-range shots to estimate muzzle-target distances. Scanning

In this study participants will learn how the Hitachi TM3000 scanning electron microscope (SEM) played a central role in one school’s movement towards Next Generation Science Standards (NGSS) and promoted exceptional student engagement. The device was used to create high quality images that were used by students in a variety of lab activities including a simulated crime scene investigation focusing on developing evidence based arguments as well as a real world conservation biology study. It provided opportunities for small group and independent investigations in support of NGSS, and peer-peer mentoring. Furthermore, use of the device was documented and were included to enhance secondary students’ college and scholarship applications, all of which were successful.

Preparing an effective workforce in high technology is the goal of both academic and industry training, and has been the engine that drives innovation and product development in the United States for over a century. During the last 50 years, technician training has comprised a combination of two-year academic programs, internships and apprentice training, and extensive On-the-Job Training (OJT). Recently, and especially in Silicon Valley, technicians have four-year college degrees, as well as relevant hands-on training. Characterization in general, and microscopy in particular, is an essential tool in process development, manufacturing and QA/QC, and failure analysis. Training for a broad range of skills and practice is challenging, especially for community colleges. Workforce studies (SRI/Boeing) suggest that even four year colleges often do not provide the relevant training and experience in laboratory skills, especially design of experiments and analysis of data. Companies in high-tech further report difficulty in finding skilled labor, especially with industry specific experience. Foothill College, in partnership with UCSC, SJSU, and NASA-Ames, has developed a microscopy training program embedded in a research laboratory, itself a partnership between university and government, providing hands-on experience in advanced instrumentation, experimental design and problem solving, with real-world context from small business innovators, in an environment called ‘the collaboratory’. The program builds on AFM-SEM training at Foothill, and provides affordable training in FE-SEM and TEM through a cost recovery model. In addition to instrument and engineering training, the collaboratory also supports academic and personal growth through a multiplayer social network of students, faculty, researchers, and innovators.

The National Nanotechnology Infrastructure Network (NNIN) is an integrated partnership of 14 universities across the US funded by NSF to support nanoscale researchers. NNIN’s education and outreach programs are large and varied and includes outreach to the K-12 community in the form of professional development workshops and school programs. Two important components of nanoscale science education are understanding size and scale and the tools used in nanoscale science and engineering (NSE). As part of our K-12 endeavors, we educate K-12 students and teachers about the tools of nanoscience by providing experiences with the Hitachi TM 3000 tabletop Scanning Electron Microscope (SEM). There are three of these across the network that are used in education and outreach. This paper will discuss approaches we use to engage the K-12 community at NNIN’s site at Georgia Institute of Technology to understand size and scale and the applications of a variety of microscopes to demonstrate the imaging capabilities of these to see both the micro and nano scales. We not only use the tabletop SEM but also include USB digital microscopes, a Keyence VHX- 600 Digital Microscope, and even a small lens used with smart phones. The goal of this outreach is to educate students as well as teachers about the capabilities of the various instruments and their importance at different size scales.

The program Project NANO (Nanoscience and Nanotechnology Outreach) enables middle and high school students to discover and research submicroscopic phenomena in a new and exciting way with the use of optical and scanning electron microscopes in the familiar surroundings of their middle or high school classrooms. Project NANO provides secondary level professional development workshops, support for classroom instruction and teacher curriculum development, and the means to deliver Project NANO toolkits (SEM, stereoscope, computer, supplies) to classrooms with Project NANO trained teachers. Evaluation surveys document the impact of the program on student’s attitudes toward science and technology and on the learning outcomes for secondary level teachers. Project NANO workshops (offered for professional development credit) enable teachers to gain familiarity using and teaching with the SEM. Teachers also learn to integrate new content knowledge and skills into topic-driven, standards-based units of instruction specifically designed to support the development of students’ higher order thinking skills that include problem solving and evidence-based thinking. The Project NANO management team includes a former university science faculty, two high school science teachers, and an educational researcher. To date, over 7500 students have experienced the impact of the Project NANO program, which provides an exciting and effective model for engaging students in the discovery of nanoscale phenomena and concepts in a fun and engaging way.

In this article we describe a novel piezoresistive cantilever technology The described cantilever can be also applied in the investigations of the thermal surface properties in all Scanning Thermal Microscopy (SThM) techniques. Batch lithography/etch patterning process combined with focused ion beam (FIB) modification allows to manufacture thermally active, resistive tips with a nanometer radius of curvature. This design makes the proposed nanoprobes especially attractive for their application in the measurement of the thermal behavior of micro- and nanoelectronic devices. Developed microcantilever is equipped with piezoresistive deflection sensor. The proposed architecture of the cantilever probe enables easy its easy integration with micro- and nanomanipulators and scanning electron microscopes.In order to approach very precisely the microcantilever near to the location to be characterized, it is mounted on a compact nanomanipulator based on a novel mobile technology. This technology allows very stable positioning, with a nanometric resolution over several centimeters which is for example useful for large samples investigations. Moreover, thanks to the vacuum-compatibility, the experiments can be carried out inside scanning electron microscopes.

The measured height of polystyrene nanoparticles varies with setpoint voltage during atomic force microscopy (AFM) tapping-mode imaging. Nanoparticle height was strongly influenced by the magnitude of the deformation caused by the AFM tapping forces, which was determined by the setpoint voltage. This influence quantity was studied by controlling the operational AFM setpoint voltage. A test sample consisting of well-dispersed 60-nm polystyrene and gold nanoparticles co-adsorbed on poly-l-lysine-coated mica was studied in this research. Gold nanoparticles have not only better mechanical property than polystyrene nanoparticles, but also obvious facets in AFM phase image. By using this sample of mixed nanoparticles, it allows us to confirm that the deformation resulted from the effect of setpoint voltage, not noise. In tapping mode, the deformation of polystyrene nanoparticles increased with decreasing setpoint voltage. Similar behavior was observed with both open loop and closed loop AFM instruments.

The axial resolution is an important parameter in Optical Coherence Tomography (OCT). In OCT a broadband light source is used to achieve high axial resolution imaging. However the dispersion results in a broadening of the coherence envelope. The dispersion mismatch between reference and sample arms then needs to be minimized to achieve optimal axial resolution for OCT. In this work we propose a new numerical dispersion compensation method to obtain ultrahigh resolution in SDOCT, in which wavelet transform instead of Fourier transform is used to obtain the signal in different frequency domain. And a series of the phase signals of different interfaces of the sample can be obtained. Under the homogeneous medium approxiamtion, the phase signal is a linear function of the wave number. Thus based on linearization of the phase signal of different interface and the wave number, the axial resolution can be improved.

Two dimensional beam deflection is often required in medical laser scanning systems such as OCT or confocal microscopy. Commonly two linear galvo mirrors are used for performance in terms of their large apertures and scan angles. The galvo mirrors are placed at the vicinity of entrance pupil of the scan lens with a “displacement distance” separating them. This distance limits the scan fields and/or reduces the effective aperture of the scan lens. Another option is to use a beam or pupil relay, and image one galvo mirror onto the other. However, beam (or pupil) relays are notoriously complicated, expensive and can add significant aberrations. This paper discusses a simple, all reflective, diffraction limited, color corrected, beam relay, capable of large scan angles and large deflecting mirrors. The design is based on a unique combination of an Offner configuration with a Schmidt aspheric corrector. The design is highly corrected up to large scan mirrors and large scan angles down to milliwaves of aberrations. It allows significantly larger scan field and or scan lenses with higher numerical aperture as compared with scanners using galvos separated by the displacement distance. While this relay is of exceptionally high performance, it has one element located where the beam is focused which may present a problem for high power lasers. Thus modifications of the above design are introduced where the beam is focused in mid air thus making it usable for high power systems such including laser marking and fabrication systems.

Scanning near-field optical microscopy (SNOM) is used to study the photo-induced deformation of layered structures containing azobenzene derivatives. This approach is particularly relevant since it allows detecting in real-time, with the same probe the surface topography and the optical field distribution at the nanoscale. The correlation between the local light pattern and the ongoing photo-induced deformation in azobenzene-containing thin films is directly evidenced for different light polarization configurations. This unveils several fundamental photodeformation mechanisms, depending not only on the light field properties, but also on the nature of the material. Controlling the projected electromagnetic field distribution allows inscription of various patterns with a resolution at the diffraction limit, i.e. of a few hundreds of nm. Surface relief patterns with characteristic sizes beyond the diffraction limit can also be produced by using the nearfield probe to locally control the photo-mechanical process. Finally, the photo-mechanical properties of azo-materials are exploited to optically patterned metal/dielectric hybrid structures. Gratings are inscribed this way on thin gold films. The characteristic features (enhancement and localization) of the surface plasmons supported by these noble metal structures are studied by near-field optical microscopy.

In this work we describe a novel kind of scanning probe microscope carried out through an optical fiber extrinsic microcavity. The micro-cavity is realized by approaching a single mode fiber to a sample placed on a piezo-scanner. The distal end of the fiber and the sample realize the optical resonator. The probe is fed by a low-coherence source and the reflected intensity is acquired by an optical spectrum analyzer. The resonant behavior of the cavity enables to overcome the conventional Rayleigh limit. For this system the transverse resolution is not defined by the NA of fiber but it is a function of the transverse electromagnetic field inside the micro-cavity. The lens-free system paves the way towards quantitative measurements in air and liquid environment.

Scanning Electron Microscopy (SEM) is widely used to measure Critical Dimensions (CD) in semiconductor lithography processes. As the size of transistors keeps shrinking, the uncertainty associated with CD-SEM accounts for a fast growing contributor to the entire manufacturing error budget. Capability to predict the metrology results from a CDSEM is highly desirable to quantify the uncertainty of metrology. Simulation has proven to be a valuable means of studying both SEM metrology and photolithography. Monte-Carlo based simulators are generally used to model the detailed image formation process of a CD-SEM, while physics-based photolithography simulations, such as PROLITH™ are commonly used for lithography modeling. However, the high computational cost limits the application of Monte- Carlo based CD-SEM simulations in conjunction with lithography simulation. We present here a compact physical CDSEM simulator which simplifies the image formation process while preserving many essential SEM imaging mechanisms. Several applications of our CD-SEM simulator are presented to demonstrate the predicting capability compared with experiments.

The defendant had three trials. The first and second ended in mistrial; the third he was convicted. Examination of the gunshot residue evidence presented in the first and third trials starkly define an extraordinary difference: science versus junk science. The defendant was convicted on the junk science.

Variation in the trend of electron flux graph in the ionosphere on the global map is common with respect to proton flux variation in inverse manner seen on diurnal basis. Continuous observation connected with the NOAA , IPS and SOHO satellite respectively of USA, Australia ,Japan and India have revealed the facts remarkably peculiar and interesting trend other than usual graph of Electron flux and solar x-ray decrease in peak level immediate prior a seismic event. An observation recorded in juxtaposition the trend of correlation establishes this fact. This typify the events like Iran 14^th April, China 17^th April 2013, with 7.8 and 7.3 MW, New Zealand 6.8 MW on 16^th August 2013, Pakistan 7.8 Mw and 6.8 Mw respectively on25^th September, and 26^th September’2013 are the supportive illustrations to the concluding concepts. The trend is also observed during the solar coronal mass ejection event. Events occur deceptively quite similar to the pre seismicity. Its diagnostic distinction can be made with the solar data available by SWPC (Australia) forecasting for solar prominences data prediction and forecasting tool. Most of the seismic phenomena are the diagnostic preseismic phenomena as the electron flux anomaly mechanism and principle clarify on the basis of fundamental laws of electrostatics and Maxwell equation of electromagnetic wave theory. This may prove a precursory tool in the seismic event forecasting and prediction technique.

RedXDefense has developed an automated red-light/green-light field presumptive lead test using a sampling pad which can be subsequently processed in a Scanning Electron Microscope for GSR confirmation. The XCAT’s sampling card is used to acquire a sample from a suspect’s hands on the scene and give investigators an immediate presumptive as to the presence of lead possibly from primer residue. Positive results can be obtained after firing as little as one shot. The same sampling card can then be sent to a crime lab and processed on the SEM for GSR following ASTM E-1588-10 Standard Guide for Gunshot Residue Analysis by Scanning Electron Microscopy/Energy Dispersive X-Ray Spectrometry, in the same manner as the existing tape lifts currently used in the field. Detection of GSR-characteristic particles (fused lead, barium, and antimony) as small as 0.8 microns (0.5 micron resolution) has been achieved using a JEOL JSM-6480LV SEM equipped with an Oxford Instruments INCA EDS system with a 50mm2 SDD detector, 350X magnification, in low-vacuum mode and in high vacuum mode after coating with carbon in a sputter coater. GSR particles remain stable on the sampling pad for a minimum of two months after chemical exposure (long term stability tests are in progress). The presumptive result provided by the XCAT yields immediate actionable intelligence to law enforcement to facilitate their investigation, without compromising the confirmatory test necessary to further support the investigation and legal case.