bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lateral beam stability of a computer assisted scanning electron microscope / x‐ray microanalysis system
Authors: Wurster R. , Lehner S. 
Published: August 2011

AbstractDigital beam control by an image analyzer has opened up new dimensions for scanning electron microscopy and x‐ray microanalysis, particularly if the feature density in the sample is high. Prior to its application to aerodynamically classified particles in the micron and submicron size range, the performance of a given system was tested by means of a special object, consisting of a pattern of micron sized holes in a metallic foil. The lateral position of the electron beam was registrated using the centre of gravity values (x‐ and y‐axis) as obtained by consecutively analyzing transmission scanning electron micrographs (bright field mode) of the special object at constant intervals.A major drift source (time dependent electrical interference field) could be detected and eliminated, thus reducing shift speeds exceeding 3 μm/h to values below 0.5 μm/h if thermally induced effects both in the electron source and related electronic circuitry were allowed to become nearly saturated. It is shown that remanence effects in the scanning coils resulting from magnification changes can produce severe sideways jumps in the beam position that must be borne in mind if unattended operation of the system is intended on features of corresponding size.
Three‐dimensional digital microscopy using the PHOIBOSl Scanner
Authors: Åslund N. , Liljeborg A. , Forsgren P.‐O. , Wahlsten S. 
Published: August 2011

AbstractNew perspectives are opened in fluorescence microscopy by combining confocal scanning with digital recording and image processing. A series of consecutive optical sections obtained by confocal scanning are used to generate a data volume that constitutes a basis for digital three‐dimensional microscopy. A description is given of an instrument system, PHOIBOS, which works according to these principles, and some representative results achieved with the system are presented. A great advantage as compared with traditional methods (e.g., using a microtome) is that the specimen is left undamaged. No artifacts are introduced as when slicing mechanically. The method can also be used to study surface topologies either in fluorescent or reflected light.
On some practical aspects of orientation determination using electron channeling patterns
Authors: Kozubowski J. A. , Ji Lii M. , Gerberich W. W. 
Published: August 2011

AbstractA brief survey was made of the methods currently used for indexing of electron channeling patterns. Special attention was given to orientation determination of individual grains in a polycrystalline sample, for trace analysis and for determination of the relative orientation of the grains. The accuracy of various procedures was tested on alpha brass samples containing annealing twins. It was found that the beam direction (z) can be routinely determined with an error of less than 0.1° and the “in‐plane” directions (x, y) with an error of less than 1°. This accuracy is sufficient to determine the slip planes in a unique manner using their slip traces on the surface. It is also sufficient to determine relative orientations of the grains with average errors of less than 0.5° in rotation angle and in the position of the rotation axis. It was shown that this accuracy seems to be sufficient for distinguishing most special, nearcoincidence grain boundaries in polycrystalline samples. Procedures used for crystallographic description of a polycrystalline specimen are discussed. These include: indexing of the channeling patterns, orientation determination of the grains, trace analysis, and misorientation (relative orientation) determination. Accuracy of these procedures is estimated through the study of twin‐oriented grains in alpha brass. Possibilities of improving the accuracy and speeding up the analytical procedures by using appropriate microcomputer programs are indicated.
Imaging and spectrometry of a microscopic gaseous target by SEM and TEM
Authors: Wurster R. 
Published: August 2011

AbstractMicroscopic gas jets are experimentally investigated using a scanning electron microscope/electron microprobe (JXA 50A, JEOL, Tokyo) equipped with a transmitted electron detector, and the CEM 902 (Zeiss, Oberkochen) which allows electron spectroscopic imaging. Both capillary microjet devices and circular orifices have been used. Imaging of the microgas jet (argon, air, artificial gas mixtures) is done by transmitted electrons (dark field), electrons as collected by the conventional Everhart‐Thomley secondary electron detector, and by electron spectroscopic imaging, both at the argon M‐ and L edges. X‐ray spectra and electron energy loss spectra taken at an axis point just a few micrometers downstream from the orifice are discussed.
The relationship between accelerating voltage and electron detection modes to linewidth measurement in an SEM
Authors: Postek M. T. , Keery W. J. , Larrabee R. D. 
Published: August 2011

AbstractThe basic premise underlying the use of the scanning electron microscope (SEM) for linewidth metrology in semiconductor research and production applications is that the video image acquired, displayed, analyzed, and ultimately measured accurately reflects the structure of interest. However, it has been clearly demonstrated that image distortions can be caused by the detected secondary electrons not originating at the point of impact of the primary electron beam and by the type and location of the secondary electron detector. These effects and their contributions to the actual image or linewidth measurement have not been fully evaluated. Effects due to uncertainties in the actual location of electron origination do not affect pitch (line center‐to‐center or similar‐edge‐location‐to‐similar‐edge‐location spacing) measurements as long as the lines have the same edge geometries and similar profiles of their images in the SEM. However, in linewidth measurement applications, the effects of edge location uncertainty are additive and thus give twice the edge detection error to the measured width. The basic intent of this work is to demonstrate the magnitude of the errors introduced by beam/specimen interactions and the mode of signal detection at a variety of beam acceleration voltages and to discuss their relationship to precise and accurate metrology.
Low‐voltage scanning electron microscopy of low‐density materials
Authors: Price C. W. , McCarthy P. L. 
Published: August 2011

AbstractDelicate microstructures in low‐density polymer foams and silica aerogel are susceptible to coating damage, artifact structures induced by coating, and electron‐beam damage when they are examined by conventional scanning electron microscopy (SEM) techniques. These problems can be reduced significantly and even eliminated when these materials are examined directly with no coating using low‐voltage scanning electron microscopy (LVSEM). Much of the fine structure in these materials also can be resolved at low voltage in a SEM equipped with a field‐emission gun (FESEM).
Calculation and comparison of the backscattering factor R for characteristic x‐ray emission
Authors: August H.‐J. , Razka R. , Wernisch J. 
Published: August 2011

AbstractThe backscattering factor R for characteristic radiation, which is a part of the atomic number correction commonly used in electron probe microanalysis, is calculated keeping mathematical simplifications at a minimum. The results are compared with the values calculated by means of three other often used expressions for the backscattering factor. It is shown that our results generally are similar to the ones of Duncumb and Reed and of Pouchou and Pichoir, but differ significantly from the ones of Love et al., whose expression seems not to be applicable if the overvoltage is higher than ∼50.
Iron‐polyethylene glycol impregnation: An attempt to reduce shrinkage of specimens in SEM preparation
Authors: Ohtsuka A. , Murakami T. 
Published: August 2011

AbstractGlutaraldehyde‐fixed HeLa cells were soaked in a mixture of fine cationic iron colloid and polyethylene glycol, immersed in tannic acid solution containing guanidine hydrochloride, and stained with osmic acid. The treated cells showed little shrinkage in the scanning electron microscope even after ethanol dehydration and CO2 critical point drying. On the assumption that every HeLa cell maintained contact with each other, preservation rate was computed as 0.975 × 0.0033 in linear dimension. Microvilli on the cell surface were well preserved, and few undersirable deposits were noted on the specimen surface. This treatment was also applicable to bulk staining of tissue blocks, such as rat kidneys. The podocyte foot processes and endothelial micropores of the glomerulus were well preserved; the epithelial cells of the Bowman's urinary capsule were not collapsed; the microvilli of the brush border of the proximal convoluted urinary tubule kept their ordinary length (2 μm).
SEM tomography: Solid‐state media and microfields
Authors: Rau E. I. 
Published: August 2011

AbstractNondestructive visualization of the internal structure of an object is necessary, for instance, in microbiology, laboratory physical experiments, and microelectronics. Computerized reconstruction tomography (CT) can be used for this purpose. This article deals with SEM‐based microtomography Examples are presented of restoring images formed with x‐rays and light [cathodoluminescence (CL)]. The potentialities of the Lorentz tomography of two‐dimensional stray magnetic fields are demonstrated.
Computer‐aided imaging: Quantitative compositional mapping with the electron probe microanalyzer
Authors: Newbury D. E. , Marinenko R. B. , Bright D. S. , Myklebust R. L. 
Published: August 2011

AbstractX‐ray area scanning (“dot mapping”) is a technique widely used in electron probe microanalysis for determining the spatial distribution of elemental constituents. Although powerful, this technique is subject to significant limitations on concentration sensitivity and flexibility for subsequent processing. The new technique of compositional mapping overcomes these limitations. In compositional mapping, a complete quantitative electron probe analysis is carried out at each point of a matrix scan. The resulting matrices of concentration values can be assembled into images in a digital image processor by assigning gray or color intensities to the actual concentrations rather than the raw spectral intensities. Digital compositional maps can be readily manipulated by a wide variety of image processing techniques to improve the visibility of features of interest.
Control of charging in low‐voltage SEM
Authors: Joy D. C. 
Published: August 2011

AbstractCharging of the specimen under electron beam irradiation is a common problem in scanning electron microscopy (SEM). It results in unstable imaging conditions and a loss in resolution due to defocus of the beam. In addition, it can cause permanent changes in some specimens from translocation of mobile ions under the influence of the induced electrostatic field. To minimize charging and its associated problems, the incident beam energy must be carefully chosen to be the value E2 at which a dynamic charge balance is obtained. This article presents data on E2 values for a variety of materials and demonstrates how E2 is affected by the choice of angle of beam incidence.
Field‐induced migration of sodium in soda silicate glasses during scanning electron microscopy
Authors: Walker T. M. , Howitt D. G. 
Published: August 2011

AbstractThe changes in chemical composition to soda silicate glass during scanning electron microscopy have been investigated. The loss of sodium from the irradiated region was measured using x‐ray wavelength spectroscopy and subsequently modelled assuming field‐assisted ionic migration. There is excellent agreement for both 20 keV and 10 keV electrons, although a radiolytic effect must probably be included to fully describe the depletion phenomenon.
Mott factors of P, V, Fe, Ga, As, Pd, In, Ta, and W for 500–3000 eV electrons
Authors: Jablonski A. , Gergely G. 
Published: August 2011

AbstractMott scattering factors are needed for the quantitative interpretation of elastic scattering phenomena in electron spectroscopy and microscopy. The inelastic mean free path of electrons has been deduced from the elastic peak intensity. The theoretical approach is based on the effective elastic cross section derived from the differential elastic cross sections. In the present work they are calculated using the partial wave expansion method, supplying as well the Mott scattering factors. Tabulated data are presented for a number of elements and 500–3000 eV electrons in steps of 2° or 5° of the scattering angle θ. The effective and total elastic scattering cross sections are also presented.
Correlation between digital differential voltage contrast and infrared microscopy analysis of latch‐up in CMOS
Authors: Muschitiello M. , Martino S. , Stucchi M. , Vanzi M. , Zanoni E. 
Published: August 2011

AbstractResults of latch‐up analysis obtained by scanning electron microscopy voltage contrast and infrared (IR) microscopy are correlated and discussed. Voltage contrast detects surface potential changes due to latch‐up firing, while IR microscopy reveals recombination radiation emitted by silicon (Si) regions where current density is maximum. Voltage contrast analysis may be difficult in very large‐scale integrated (VLSI) circuits because well and substrate regions can be masked by overlying conductors. On the contrary, thanks to the transparency of Si to IR radiation, IR microscopy can detect latch‐up by observing the reverse of the device and is not limited by a high metal density.
Three‐colour x‐ray mapping using digital storage
Authors: Dhariwal R. S. , McClean J. A. , Hjelmfoss I. M. 
Published: August 2011

AbstractComputer‐controlled scanning of a scanning electron microscope (SEM) fitted with an energy‐dispersive x‐ray analyser has been carried out. This has been achieved by building an SEM interface module which controls the scanning of the electron beam and also provides a communication link between the x‐ray analyser and an enhanced BBC micro. The digitised x‐ray data pulses can be collected from three elements simultaneously to produce colour‐coded x‐ray distribution maps. Some such maps from two different specimens are presented and an effect of x‐ray shadowing is clearly demonstrated. A comparison between images acquired using a frame size with 256 × 256 pixels and those with 128 × 128 pixels is made.
EDS analysis of polyphase microstructures—with application to Al‐Si‐Mg2Si
Authors: O'Brien D. M. , Sharp R. M. , Stringer D. J. 
Published: August 2011

AbstractThe effect of different phase densities in biasing the overall analysis obtained from an EDS spectrum of a scanned area of a polyphase material is examined. Procedures to correct this bias using both pure element and polyphase standards are developed and tested using unidirectionally solidified Al‐Si, Al‐Mg2Si, and Al‐Si‐Mg2Si eutectic materials. It is shown that the correction is most marked when the standards and the unknown have dissimilar microstructures, and that the procedure is useful, although it usually did not fully correct the analyses.
A comparison of recently developed correction procedures for electron probe microanalysis
Authors: Sevov S. , Degischer H. P. , August H.‐J. , Wernisch J. 
Published: August 2011

AbstractThree recently developed absorption and atomic number correction procedures have been investigated with regard to possible improvements and to the performance of these improved models, which has been studied depending on different values of the absorption correction factor. The test file includes 655 measurements of elements with Z > 10 and 258 B‐, C‐, and N‐measurements. The results show that the models of Bastin and Heijligers and of Sewell, Love, and Scott generally are substantially better than the one of Tan‐uma and Nagashima or the established ZAF approach.
A data acquisition and image processing system for scanning tunneling microscopy
Authors: Fuchs H. , Eustachi W. , Seifert R. 
Published: August 2011

AbstractWe have built a dedicated data acquisition and image processing system for scanning tunneling microscopy (STM). Data acquisition is accomplished by a fast 8‐bit add‐on frame grabber which may be synchronized either to standard TV frequencies or to asynchronous slow scan data sources such as STM or SEM. A 32‐bit minicomputer is used for image processing by means of a comprehensive interactive‐language which also allows the data acquisition process to be controlled. To speed up time‐consuming computations, a floating‐point array processor was linked to the system.
Combining confocal and conventional modes in tandem scanning reflected light microscopy
Authors: Boyde A. 
Published: August 2011

AbstractThe addition of transmitted illumination to the tandem scanning reflected light microscope enables it to be used with most conventional modes to discover a location of interest in a prepared sample, but still to use confocal modes when desired. The depth of field for the nonconfocal transmitted light image can be controlled by the aperture of illumination. Conventional and confocal coloured images can be mixed in any proportion within the same frame.
Analysis of an altered simple silicate glass using different mineral and glass standards
Authors: Mazer J. J. , Bates J. K. 
Published: August 2011

AbstractQuantitative analyses of alteration products formed during the aqueous corrosion of glass were performed using four different sets of standards: relevant mineral standards, an NBS glass standard, unreacted simple silicate glass, and the unreacted center of the reacted glass. A simple silicate glass (containing Na, Mg, Al, Si, and Ca) was reacted in water vapor at 200° C for 14 days. Up to eight alteration phases, including a Mg‐rich smectite clay and a zeolite intermediate in composition between Ca‐harmotome and phillipsite, formed on the glass surface. A set of energy‐dispersed spectra (EDS) of the bulk glass, the clay, and the zeolite were collected from a polished cross‐section of the reacted sample. The sum of the elemental weight percents varied by as much as 48% using the different standards. These differences are due to poor electrical conductivity through the clay layer. When the analyses were normalized to 100%, the differences between analyses using the standards were small (less than 10 wt% for individual cations and <5 total wt%). Normalization is inappropriate in the analysis of hydrated alteration phases, which contain a significant amount of water. The inability of the EDS system to detect water requires that absolute analyses be used to estimate the water content of the alteration phases. The bulk glass standard analyses were best suited for this purpose. In addition, use of the bulk glass standard is preferable in our application because spectra of the altered layer and bulk glass can be acquired from the same specimen. Analytical errors that may occur due to poor conductivity through the reacted layer, drifting probe currents, or varying thickness of the carbon coating are also reduce.
Ion beam‐sputtered and magnetron‐sputtered thin films on cytoskeletons: A high‐resolution tem study
Authors: Lindroth M. , Sundgren J‐E. 
Published: August 2011

AbstractA comparison of ion beam‐sputtered and magnetron‐sputtered thin platinum (Pt) and tungsten (W) films was made. Cytoskeletons from detergent extracted glioma cells grown on gold grids were coated with Pt or W at thicknesses of 1, 1.5, and 2.5 nm. Transmission electron micrographs were taken at high magnification and the granularity of the metal films was evaluated both on the Formvar film and the filaments of the cytoskeleton. In order to make a comparison between the two deposition methods, the metal deposition rate must be equal when corresponding thicknesses are made. Since ion beam sputtering generally is a slower process than magnetron sputtering, an increased target to specimen distance was necessary with the latter technique. This resulted in a coarser granularity of the W films as compared with the ion beam sputtered. The Pt, however, showed no marked difference between the two techniques at equal deposition rates. The study also demonstrated that varying the deposition rate caused differences in the granularity of the magnetron‐sputtered Pt and W films, even if the voltage of the target was kept constant. Decreasing the target to specimen distance which increased the deposition rate resulted in a finer granularity of both the Pt and the W films. At the highest deposition rate the granularity of both the Pt and W films was comparable with the granularity of the ion beam‐sputtered films.
Comparison of basic principles of the surface‐specific analytical methods: AES/SAM, ESCA (XPS), SIMS, and ISS with X‐ray microanalysis, and some applications in research and industry
Authors: Hantsche H. 
Published: August 2011

AbstractModern analytical methods for the investigation of surfaces have been greatly improved during the last decade, and the number of instruments offered by manufacturers has increased accordingly. In this article, four of the most frequently applied methods are discussed, with emphasis on those which have found wider application in industry. The aim of this report is to give an easily understandable introduction to all those who are not yet familiar with surface analytical methods. Emphasis is on the Auger electron spectroscopy (AES), the most popular technique for elemental analysis of surfaces. The numerous analytical methods differ widely in information depth, lateral resolution, level of nondestructiveness, detection limits, and the possibility of getting quantitative results. Compared with the well known x‐ray microprobe analysis, the surface‐sensitive methods have a lower information depth of up to four orders of magnitude and are therefore well suited to analyze extremely thin films down to a few atomic layers. First, the fundamental physical principles of the atomic excitation and emission processes are described, then the main characteristics of the four methods and their information content are discussed. Finally, some applications are given for the characterization of interesting technical materials.
Backscatter Kikuchi diffraction in the SEM for identification of crystallographic point groups
Authors: Baba‐Kishi K. Z. , Dingley D. J. 
Published: August 2011

AbstractA preliminary account is given of the application of backscatter Kikuchi diffraction patterns (BKP) to point group determination in the SEM. Studies carried out on bulk specimens selected from the 32‐point groups indicate that 27 of the 32‐point groups can be determined unambiguously using BKPs, though distinction between 6,6,4,4 and 3 and 3 is difficult and requires special procedures. Evidence for breakdown of Friedel's law was observed in BKPs from GaSb, thus confirming the noncentrosymmetric point group 43m. Differences in intensities observed between the reflections hkl and hk̄l̄ reflections in GaSb which arise from the sensitivity of dynamical interactions to phases of the structure factors, could not be found in GaAs, illustrating that point group determination using BKPs should be considered with caution.