Proceedings Volume 8729

Scanning Microscopies 2013: Advanced Microscopy Technologies for Defense, Homeland Security, Forensic, Life, Environmental, and Industrial Sciences

Michael T. Postek, Dale E. Newbury, S. Frank Platek, et al.
cover
Proceedings Volume 8729

Scanning Microscopies 2013: Advanced Microscopy Technologies for Defense, Homeland Security, Forensic, Life, Environmental, and Industrial Sciences

Michael T. Postek, Dale E. Newbury, S. Frank Platek, et al.
View the digital version of this volume at SPIE Digital Libarary.

Volume Details

Date Published: 6 June 2013
Contents: 6 Sessions, 16 Papers, 0 Presentations
Conference: SPIE Defense, Security, and Sensing 2013
Volume Number: 8729

Table of Contents

icon_mobile_dropdown

Table of Contents

All links to SPIE Proceedings will open in the SPIE Digital Library. external link icon
View Session icon_mobile_dropdown
  • Front Matter: Volume 8729
  • Opening Keynote Session
  • Advancements in Scanning Probe Microscopy
  • STEM Workshop
  • Advancements in Scanning Microscopies
  • Particle Beam Interaction Modeling Workshop
Front Matter: Volume 8729
icon_mobile_dropdown
Front Matter: Volume 8729
This PDF file contains the front matter associated with SPIE Proceedings Volume 8729, including the Title Page, Copyright Information, Table of Contents, and the Conference Committee listing.
Opening Keynote Session
icon_mobile_dropdown
Scanning electron microscopy/energy dispersive spectrometry fixedbeam or overscan x-ray microanalysis of particles can miss the real structure: x-ray spectrum image mapping reveals the true nature
Dale E. Newbury, Nicholas W. M. Ritchie
The typical strategy for analysis of a microscopic particle by scanning electron microscopy/energy dispersive spectrometry x-ray microanalysis (SEM/EDS) is to use a fixed beam placed at the particle center or to continuously overscan to gather an “averaged” x-ray spectrum. While useful, such strategies inevitably concede any possibility of recognizing microstructure within the particle, and such fine scale structure is often critical for understanding the origins, behavior, and fate of particles. Elemental imaging by x-ray mapping has been a mainstay of SEM/EDS analytical practice for many years, but the time penalty associated with mapping with older EDS technology has discouraged its general use and reserved it more for detailed studies that justified the time investment. The emergence of the high throughput, high peak stability silicon drift detector (SDD-EDS) has enabled a more effective particle mapping strategy: “flash” x-ray spectrum image maps can now be recorded in seconds that capture the spatial distribution of major (concentration, C > 0.1 mass fraction) and minor (0.01 ≤ C ≤ 0.1) constituents. New SEM/SDD-EDS instrument configurations feature multiple SDDs that view the specimen from widely spaced azimuthal angles. Multiple, simultaneous measurements from different angles enable x-ray spectrometry and mapping that can minimize the strong geometric effects of particles. The NIST DTSA-II software engine is a powerful aid for quantitatively analyzing EDS spectra measured individually as well as for mapping information (available free for Java platforms at: http://www.cstl.nist.gov/div837/837.02/epq/dtsa2/index.html).
Does your SEM really tell the truth? Part 2
Michael T. Postek, András E. Vladár, Kavuri P. Purushotham
The scanning electron microscope (SEM) has gone through a tremendous evolution to become indispensable for many and diverse scientific and industrial applications. The first paper in this series, discussed some of the issues related to signal generation in the SEM, instrument calibration, electron beam interactions and the need for physics-based modelling to understand the actual image formation mechanisms. All these were summed together in a discussion of how these issues effect measurements made with the instrument. This second paper discusses another major issue confronting the microscopist which is specimen contamination. Over the years, NIST has done a great deal of research into the issue of sample contamination and its removal and elimination and some of this work is reviewed and discussed here.
Electron microscopy and forensic practice
Marek Kotrlý, Ivana Turková
Electron microanalysis in forensic practice ranks among basic applications used in investigation of traces (latents, stains, etc.) from crime scenes. Applying electron microscope allows for rapid screening and receiving initial information for a wide range of traces. SEM with EDS/WDS makes it possible to observe topography surface and morphology samples and examination of chemical components. Physical laboratory of the Institute of Criminalistics Prague use SEM especially for examination of inorganic samples, rarely for biology and other material. Recently, possibilities of electron microscopy have been extended considerably using dual systems with focused ion beam. These systems are applied mainly in study of inner micro and nanoparticles , thin layers (intersecting lines in graphical forensic examinations, analysis of layers of functional glass, etc.), study of alloys microdefects, creating 3D particles and aggregates models, etc. Automated mineralogical analyses are a great asset to analysis of mineral phases, particularly soils, similarly it holds for cathode luminescence, predominantly colour one and precise quantitative measurement of their spectral characteristics. Among latest innovations that are becoming to appear also at ordinary laboratories are TOF - SIMS systems and micro Raman spectroscopy with a resolution comparable to EDS/WDS analysis (capable of achieving similar level as through EDS/WDS analysis).
Advancements in Scanning Probe Microscopy
icon_mobile_dropdown
A large range metrological atomic force microscope and its uncertainty analysis
S. Gao, Q. Li, W. Li, et al.
The atomic force microscope (AFMs) is widely used in nanotechnology research and industry. To ensure the quantity consistency, the measurement precision of these machines must be calibrated and trace back to SI international unit. In the calibration process, first the standard grating pitch artifact is calibrated by metrological atomic force microscope which has the direct tracing capability; then the grating pitch artifact is transferred to calibrate the common AFMs. Because the importance of metrological atomic force microscope in nanometer tracing, the NIM of China has developed a large range metrological atomic force microscope with 50mm×50mm×2mm scan area. In this paper, the structure and performance of this instrument will be introduced briefly. The instrument utilizes a series of novel designs like hybrid air bearing and sliding guide platform, three dimensional orthogonal piezo scanner head, multi-pass interferometer and Fourier harmonic components separation method to achieve both high precision measurement in small area and fast measurement in large area. As a metrological instrument, the error sources and uncertainties of mAFM are also analyzed, theoretical analysis and experiments show the standard uncertainty of the mAFM is less than 2nm in small range and 20nm in large range
Performance improvement of a large range metrological AFM through parasitic interference feedback artifacts removing by using laser multimode modulation method
Qi Li, Sitian Gao, Wei Li, et al.
A large range multi-functional metrological atomic force microscope based on optical beam deflection method has been set up at NIM one year ago. Being designed intended to make a traceable measurement of standard samples, the machine uses three axes stacked piezoceramic actuators, each axis with a pair of push-pull piezo operated at opposite phases to make orthogonal scanning with maximized dimensional up to 50×50×2mm3. The stage displacement is measured by homodyne interferometer framework in x,y,z direction, from which beams are aligned to intersect at cantilever tip to avoid Abbe error, an eight times optical path multiplier interferometer mirror is researched to enhance fringe resolution. There is also a new compact AFM head integrated with LD, quadrant PD, cantilever, optical path and microscope, the head uses special track lens group to guarantee laser spot focused and static on the back of the cantilever, no matter whether or not the cantilever have lateral movements; similarly, reflect beam also focused and static in the center of quadrant detector through convergence lens group, assumed no cantilever bending on vertical direction. Attribute to above design, the AFM have a resolution up to 0.5nm. In the paper, further improvement is described to reduce the influence of parasitic interference caused by reflection from sample surface using laser multimode modulation, the results shows metrological AFM have a better performance in measuring step, lateral pitch, line width, nanoroughness and other nanoscale structures.
STEM Workshop
icon_mobile_dropdown
HTA educational outreach program and change the equation participation
Robert Gordon
In this presentation, Hitachi High Technologies America (HTA) introduces its Educational Outreach Program and explains it’s involvement with Change The Equation (CTEq), a nonprofit, nonpartisan, CEO-led initiative that is mobilizing the business community to improve the quality of science, technology, engineering and mathematics (STEM) learning in the United States.
Bringing students to the mountain: developing partnerships to introduce students to cutting-edge research
Anne Lynn Gillian-Daniel, Robert J. Gordon, Benjamin L. Taylor, et al.
Many materials science education and outreach activities are designed to be easy and cost-effective to implement in K- 12 classrooms. While these activities are extremely effective at teaching broad materials science concepts such as size and scale, materials properties, and the use of tools in science, they do not connect very closely to the work being done in materials science research laboratories. In an effort to more closely connect our outreach efforts to the work being done by our researchers, the University of Wisconsin–Madison’s Materials Research Science and Engineering Center (UW-MRSEC) has developed a partnership with Hitachi High Technologies America, Inc. This partnership allows us to introduce public audiences to a state-of-the-art tabletop scanning electron microscope (SEM) that is being used by UW researchers. In this paper, we describe the partnership including the use of the SEM in our Research Experience for Teachers (RET) program and in our community outreach programs.
Using the Hitachi TM 3000 in a middle school classroom
Mary Ellen Wolfinger
In this presentation, Mary Ellen Wolfinger explains how the Hitachi TM 3000 scanning electron microscope was used in her sixth grade science classroom to incorporate science, technology, engineering and mathematics (STEM) education.
Implementing STEM technology in a Title One middle school classroom
Carolyn Holcomb
What do a modern day CSI forensics lab and an electron microscope have in common? It offers the ability to engage students in a scientific investigation, exploring the world of nanotechnology using modern day equipment. 7th grade students at Western Heights Middle School at Hagerstown, MD, used Hitachi’s TM3000 to better understand how technology is utilized when investigating contemporary questions. Using the TM3000, students learned how to load samples, scan, take pictures, and focus the SEM. This experience was an eye opener to students who otherwise would never have had such a learning opportunity. As a result many verbalized interest in pursuing careers in STEM related fields, if only to be able to use such fun equipment. In this session the teacher will present how the instrument was used, and the lessons learned both by the instructor and her students.
Integrating independent research into science curricula to foster STEM leadership
Craig Queenan, Alyssa Calabro, David Becker
Preparing students for college and future careers is one of the main goals of K-12 education, but current STEM teaching methods do not do enough to interest students and leave them prepared to enter into and succeed in STEM careers. While measures to implement unifying standards for science education across the country are aimed at ensuring that all students are taught the same material at each grade level, a shift in the way science is taught to is needed to complete the redesign of science education. The independent research model described here aligns with the new content standards and focuses on developing the principles of perspective, purpose, resources, collaboration, analysis, and presentation. These principles not only engage students in the classroom, but also leave students prepared to enter into science programs in college and succeed in leadership roles in the STEM workforce.
Advancements in Scanning Microscopies
icon_mobile_dropdown
Advances in photo-thermal infrared imaging microspectroscopy
There is a growing need for chemical imaging techniques in many fields of science and technology: forensics, materials science, pharmaceutical and chemical industries, just to name a few. While FTIR micro-spectroscopy is commonly used, its practical resolution limit of about 20 microns or more is often insufficient. Raman micro-spectroscopy provides better spatial resolution (~1 micron), but is not always practical because of samples exhibiting fluorescence or low Raman scattering efficiency. We are developing a non-contact and non-destructive technique we call photo-thermal infrared imaging spectroscopy (PT-IRIS). It involves photo-thermal heating of the sample with a tunable quantum cascade laser and measuring the resulting increase in thermal emission with an infrared detector. Photo-thermal emission spectra resemble FTIR absorbance spectra and can be acquired in both stand-off and microscopy configurations. Furthermore, PT-IRIS allows the acquisition of absorbance-like photo-thermal spectra in a reflected geometry, suitable for field applications and for in-situ study of samples on optically IR-opaque substrates (metals, fabrics, paint, glass etc.). Conventional FTIR microscopes in reflection mode measure the reflectance spectra which are different from absorbance spectra and are usually not catalogued in FTIR spectral libraries. In this paper, we continue developing this new technique. We perform a series of numerical simulations of the laser heating of samples during photo-thermal microscopy. We develop parameterized formulas to help the user pick the appropriate laser illumination power. We also examine the influence of sample geometry on spectral signatures. Finally, we measure and compare photo-thermal and reflectance spectra for two test samples.
Surface optical properties for copper based on surface Kramers-Kroning analysis
T. Tang, Z. M. Zhang, K. Tőkési, et al.
Differential surface excitation probability for medium energy electrons traveling in Cu is extracted from reflection electron energy loss spectra using various theoretical models and the Werner’s elimination-retrieved algorithm. While the reflection electron energy loss spectra of Cu thin film were measured by the hemispherical analyzer, the bulk spectra of Cu were recorded by a cylindrical mirror analyzer. Surface Kramers-Kronig dispersion relationship is employed to analyze the surface energy loss function and to derive the complex dielectric constant. We found that the obtained surface optical data approximate reasonably well the optical properties of surface layer.
Particle Beam Interaction Modeling Workshop
icon_mobile_dropdown
Monte Carlo simulation of realistic beam-sample interaction in SEM: application to evaluation of sharpness measurement methods
Z. Ruan, S. F. Mao, P. Zhang, et al.
Monte Carlo simulated SEM images for realistic instrumental conditions are used to evaluate measurement methods for SEM image sharpness. The Monte Carlo simulation of the SEM image is based on a well-developed physical model of electron-solid interaction, which employs Mott’s cross section for elastic electron scattering and dielectric functional approach to electron inelastic scattering with cascade secondary electron production included, a finite element mesh modeling of complex sample topography and a modeling of SEM instrumental conditions (i.e. focus, astigmatism, drift and vibration). A series of simulated SEM images of a realistic sample, gold particles on a carbon substrate, for different instrumental parameters are generated to represent practical images where all instrumental conditions are precisely known and controlled. An estimation of three measurement methods of SEM image sharpness, i.e. FT, CG and DR methods, has then been performed with these simulated images. The responses of image sharpness measurement methods to various instrumental conditions are studied. The calculation shows that all the three methods present similar and reasonable response to focus parameter; their dependences of the measured sharpness on astigmatism coefficient are complicated and CG method presents reasonable sharpness value. For drift and vibration, the situation is more complex because CG/DR methods can be less or more sensitive to vibration coefficient than FT method. Because of the different response behaviors of the three sharpness measurement methods to experimental parameters, we propose to use a mean, simple average or weighted average, of three sharpness values as a proper measure of sharpness.
Monte Carlo study of the influence of electron beam focusing to SEM linewidth measurement
P. Zhang, S. F. Mao, Z. M. Zhang, et al.
Based on a Monte Carlo simulation method we have analyzed the influence of electron beam focusing to linewidth measurement for Si trapezoid lines by scanning electron microscopy (SEM) image. The electron probe focusing with finite probe width due to aberration is considered by two different models for simulating incident electron trajectories. The simulation result shows that on the specimen surface the electron beam profile is deviated from the Gaussian probe shape because of the surface topography; the measured linewidth then depends on the focus position and aperture angle.
Monte Carlo simulation of x-ray photoemission electron microscopic image
Z. M. Zhang, T. Tang, S. F. Mao, et al.
A new Monte Carlo method is built to describe the generation and transport processes of photoelectrons excited by incident X-ray. XPEEM images for Ag- and Au-dot array on substrate Si are simulated at different incident conditions by the Monte Carlo method. The trajectories of electrons scattered near dot sides and substrate surface were given to visualize the photoelectron penetrating processes. The simulated XPEEM images in TEY mode are found very close to the experimental observations.