bluuebunny/crossref_metadata_2025 huggingface dataset:
Volume changes during preparation of mouse embryonic tissue for scanning electron microscopy
Authors: Boyde A. , MacOnnachie E.
Published: August 2011

This paper describes the results of experiments in which the volume changes in mouse embryo limb samples were followed more or less continuously after fixation through dehydration and critical point drying, with in some instances data relating to post critical point drying shrinkage.

14 and 15 day p. c. mouse embryos were fixed in 3 % glutaraldehyde in cacodylate buffer and stored in this fixative until use. Single specimens were studied using a Quantimet image analysing computer to record the changes in projected area of the unmounted specimens as they were passed through the usual series of reagents according to various commonly used dehydration schedules. The area changes were converted to volume changes for the purposes of presentation in this paper. The Quantimet system could not be used to follow volume changes in the CPD bomb so that most experiments detail the volume in the intermediate fluid before CPD and the size of the specimen immediately after it was removed from the CPD bomb. A few experiments were conducted in which the specimens were measured whilst they were in the CPD bomb. The measurements relating to dehydration and CPD procedures were compared with measurements of air dried and freeze dried specimens.

All three drying methods cause considerable shrinkage: freeze drying to 85 % of the glutaraldehyde fixed tissue volume; critical point drying to 41% (after 24 h); and air drying from a volatile solvent to about 18% of the fixed tissue volume. Air drying from water caused a shrinkage to about 12% of the original volume. There was no significant difference between the various commonly used CPD schedules or between GA only and GA + Os O4 fixed tissue. CPD via cellosolve and CO2 caused substantially more shrinkage than other methods.

Dimensional changes during specimen preparation are probably associated with changes in shape and in relative relationships between organelles, cells and tissues having different compositions. This should be borne in mind by all those interpreting scanning electron micrographs of dried animal soft tissue specimens.
A preliminary study of the application of SEM to the study of coins
Authors: Kushelevsky A. P. , Meshorer Y.
Published: August 2011

The superior depth of focus of the SEM at low and high magnification provides important information regarding the minting techniques used to produce the coin. This information can be used as an additional criterion to authenticate questionable coins. The importance of preserving surface structure during cleaning processes of ancient coins is stressed.
Automatic electron microprobe analysis using energy dispersive spectrometry
Authors: Beswick J. M.
Published: August 2011

The use of mini computers in energy dispersive spectrometry is common in quantitative electron microprobe analysis. A modification to the Edax 707 multichannel analyser makes it possible to control the stage movement of an electron beam instrument via a suitable motor control unit and to restart the multichannel analyser. By use of a loop in the BASIC interactive computer programme any number of automatic microanalysis step determinations can be performed.
Problems with the preparation of blood vessels for scanning electron microscopy a critical review
Authors: Hollweg H. G. , Buss H.
Published: August 2011

The application of the scanning electron microscope (SEM) in the investigation of blood vessels in the last ten years is reviewed. Methodological differences from anesthesia of the experimental animal to mounting of the dried tissue specimen are discussed. Some of the major interpretative pitfalls are indicated and some practical guidelines for standardization are offered.
Depth profiling by secondary ion mass spectrometry
Authors: Zinner E.
Published: August 2011

The principles and applications of depth profiling by secondary ion mass spectrometry (SIMS) are reviewed. Discussed are the basic physical processes and instrumental factors which influence the shape of depth profiles and which have to be understood or controlled for successful experimental measurements. Microroughness caused by sputtering, atomic mixing by primary beam knock‐on, and sample consumption limit the depth resolution which can be achieved while the chemical effect of ion yield enhancement by reactive species, matrix effects, and preferential sputtering can strongly affect the secondary ion signal. Instrumental effects to be controlled include beam uniformity, sample charging, and beam, and residual gas contamination. High depth resolution and sensitivity are the reasons for a wide variety of applications for SIMS depth profiling. Reviewed are measurements of the range distribution of ions implanted into semiconductors and their redistribution by subsequent annealing, studies of thin films and of oxide layers, diffusion measurements in metals, semiconductors, and minerals, measurements of elemental surface enhancements in airborne particles, and lunar glass spherules, and the search for solar wind implanted ions in lunar crystals.
SIMS instrumentation and imaging techniques
Authors: Liebl H.
Published: August 2011

Secondary ion mass spectrometry (SIMS) has evolved as a technique for characterizing solids and surfaces which is distinguished by high sensitivity and its applicability to all elements. It can be used for surface research, in‐depth concentration profiling, isotopic work, and the identification of compounds. Combined with imaging techniques, these applications can be made with high spatial resolution. In this respect, ion probe microanalysis complements electron probe microanalysis (XRMA and scanning AES).
Conductive staining in SEM with especial reference to tissue transparency
Authors: Gunji T. , Wakita M. , Kobayashi S.
Published: August 2011

Although the number of applications of conductive staining for SEM has recently increased investigations or discussions on the features of these methods are scanty, and so it could not be said that its features are sufficiently understood. In the present studies employing the tannin‐osmium method as the conductive stain, the authors compared it with an ion‐sputtering method that they use for metal coating.

Besides the prevention of masking by the coating metal, there are other advantages to the conductive staining method.

The appearance of the tissue “transparency”, which allows three‐dimensional observations of sub‐surface structures to be made.

Any damage associated with metal coating can be avoided since the specimen itself is conductive.

Hardening of specimens by the conductive stain enhances the resistance of structures to mechanical damage during preparation.

Especially the tissue transparency produced by the conductive stain might suggest new possibilities for SEM.
Preservation of the microbial association to intestinal mucosal epithelium in rats for scanning electron microscopy
Authors: Schellenberg D. A. , Pangborn J.
Published: August 2011

A preparation technique for scanning electron microscopy (SEM) of the luminal surface of the intestinal mucosa was developed, with the objective of preserving the delicate interface between the microbial flora and the mucosal surface. The technique allows observation of the bacterial polysaccharide filaments and the structural features of the intestinal epithelium.
Preparation method for SEM and X‐ray projection microscopy of mouse embryos
Authors: Claussen C.‐P. , Louton M. , Hämel‐Hans D.
Published: August 2011

In this paper we described a new preparation method: Routine Bouin fixation of mammalian tissues (e.g. mouse‐embryos) allows not only light microscopy, but also SEM and x‐ray microscopic studies on the same samples. Bouin's fixative combined with 3% OsO4 postfixation gave best contrast in SEM and x‐ray projection microscopy.
The application of SEM and XRMA to the study of the structure and composition of Spanish mercury ores. A genesic hypothesis
Authors: Calvo F. A. , Guilemany J. Ma. , Ma de Salazar J. Gomez
Published: August 2011

This paper reports the results obtained by SEM and XRMA on the structure and constituents composition of different Spanish mercury ores. A new hypothesis to explain its genesis is proposed. Bearing in mind similarities and differences in the nature and number of minerals present and, their distribution on the ore, operations for more convenient beneficiation processes are suggested. Samples from Almadén (Ciudad Real), Caunedo (Oviedo), Tarna (León) and Chovar (Castellón), were studied.
Material surfaces for electron‐optical equipment
Authors: Anger K. , Lischke B. , Sturm M.
Published: August 2011

Electron‐beam inspection systems for VLSICs and electron‐beam pattern generation require exact positioning of the electron beam on the specimen. In this connection the question arises as to what properties the walls and diaphragms in the ambience of the path of the electron beam are required to have with respect to material, surface layers and cleanness in order to exclude their collecting electric charges that will undesirably influence the electron beam.

Experimental investigations of this problem by means of electron‐shadow projection show that the conductivity of a material should not be the sole criterion for its choice, but that its behavior under exposure to backscattered electrons and secondary electron emission must also be taken into account. Graphite of poor conductivity was found to be particularly favorable. Electroplated surfaces are often less favorable than untreated surfaces. Magnetic materials always exhibit minor defects. For cleaning, a carefully controlled ultrasonic technique using conventional cleaning agents is necessary and sufficient.
A semiconductor electron current detector for the direct recording of electron microscopic diffraction images
Authors: Fuchs H. , Schuler M.
Published: August 2011

A semiconductor detector for the direct time‐serial recording of electron microscopic diffraction images is presented. The recording method is described and the performance of the detector compared to that of a standard STEM scintillator/photomultiplier chain.
Colour micrographs for backscattered electron signals in the SEM
Authors: Danilatos G. D.
Published: August 2011

The backscattered electron (BSE) signals detected by a pair of detectors in the SEM can be used for producing colour micrographs. The image corresponding to any of these signals, or to a mixture of these signals, is assigned one primary colour and two or more of these images are superimposed onto the same colour frame. In addition, the mixing of signals from the gaseous detector device together with their use for colour imaging is also examined.
An SEM based system for a complete characterization of latch‐up in CMOS integrated circuits
Authors: Canali C. , Fantini F. , Giannini M. , Senin A. , Vanzi M. , Zanoni E.
Published: August 2011

An electron beam testing system was established for a complete and detailed analysis of latch‐up in CMOS integrated circuits. Problems which can be studied include:

identification of latch‐up current paths in steady state condition;

measurement of the local latch‐up sensitivity of the various parts of the circuit;

observation of the time evolution of latch‐up from the firing event to the final condition.
A straining test within an SEM and its application
Authors: Xu Y. B.
Published: August 2011

This paper describes a straining a test within an SEM and its application to the following problems:

ductile fracture of metallic materials,

cleavage fracture by slip,

shear cracking,

deformation and fracture in lamellar pearlite.
A Further Improvement in the Gaussian ϕ(ϱ) Approach for Matrix Correction in Quantitative Electron Probe Microanalysis
Authors: Bastin G. F. , Heijligers H. J. M. , van Loo F. J. J.
Published: August 2011

An improved correction model for quantitative electron probe microanalysis, based on modifications of the Gaussian ϕ(ϱ) approach, originally introduced by Packwood and Brown, is presented. The improvements consist of better equations for the input parameters of this model which have been obtained by fitting to experimental ϕ(ϱ) data. The new program has been tested on 627 measurements for medium to heavy elements (Z>11) and on 117 carbon measurements with excellent results: an r.m.s. value of 2.99% in the former case and 4.1% in the latter. Finally the new program has been compared to five other current correction programs which were found to perform less satisfactorily.
Intensity gradient techniques for orientation analysis of electron micrographs
Authors: Tovey N. K. , Smart P.
Published: August 2011

The variation in intensity between neighbouring picture points on an electron micrograph may be used to define an intensity gradient vector. This vector is related to the orientation of the feature at that point, and may be compared with similar vectors at all other points within the micrograph to obtain a quantitative measure of anisotropy. Alternatively, the results may be displayed graphically as a rosette diagram. This paper compares the results from using a simple ‘5‐point’, i.e. the nearest neighbours with those from alternative formulations for the intensity gradient vector. Generally, the increased number of points improves the shape of the rosette diagram by minimizing the likelihood of pronounced ‘spikes’ at certain critical angles which is a feature of the ‘5‐point’ method. The improved analysis requires an extra 60% computing time, which may be of significance if direct on‐line work is contemplated. Some examples of micrographs of soil microfabric are presented to illustrate the different methods.
Reduction of edge penetration effect in the scanning electron microscope
Authors: Wells Oliver C.
Published: August 2011

Electron penetration into the sample in the scanning electron microscope can give rise to bright fringes close to sharp edges in the secondary electron image. This can make it difficult to see details close to the edge. These fringes can be considerably reduced by putting a positive control electrode (CE) between the specimen and the collector. This can be mounted with an insulated clip directly onto the specimen stub. The effectiveness of this technique is demonstrated for the case of a cleaved silicon wafer containing microelectronic structures. The action of the CE is explained in terms of the effective solid angle subtended by the collector at the surface of the specimen.
Stereological stereometry: Simplified approaches to volumetry by SEM
Authors: Boyde A.
Published: August 2011

New approximate methods for the measurement of volumes of pits in otherwise flat substrates are outlined: all are based on taking parallax measurements from SEM stereo‐pair images. The measured points lie at pre‐set intervals in a grid, the grid corresponding to the usual 2‐D array used in stereology and being used for the same purpose – that of determining area. Depth below the original surface is derived from the parallax at each point. Several practical alternatives for parallax measurement are considered, all involving relatively inexpensive instruments. The cheapest – and it remains to be determined whether also the most efficient – involves the use of a stereo‐pair grid overlay, called a “2D‐3D” grid. This grid exists physically in only two dimensions, but is seen to exist apparently in three dimensions.
TEM‐, SEM‐ and STEM‐studies of sputter‐coated cytoskeletons
Authors: Lindroth M. , Bell P. B. , Fredriksson B. A.
Published: August 2011

A technique for sputter coating of cytoskeletons from detergent extracted cells is described. The method allows their study in high resolution TEM, SEM and STEM. The use of cytoskeletons is also a valuable model system for the evaluation of metal coating techniques, allowing studies of deposited metal on fine filamentous structures of varying thicknesses.

Pt and W were sputtered at 1 to 5 nm, and comparisons were made with reference to contrast and granularity. Both metais gave good topographical contrast, but Pt showed a coarse structure and a greater decorating tendency than W.

The method provides a simple system for studies of the three‐dimensional cytoskeletal organization, without the use of cumbersome replica‐techniques.
A new method for pulmonary edema research: Scanning electron microscopy of frozen‐hydrated edematous lung
Authors: Hook G. R. , Bastacky J. , Conhaim R. L. , Staub N. C. , Hayes T. L.
Published: August 2011

We present an integrative method for studying alveolar fluid accumulation during pulmonary edema using scanning electron microscopy (SEM) of frozen‐hydrated lung. We induced edema in dogs by fluid over‐loading the vascular system while monitoring vascular and airway pressures. Terminally, we freeze‐fixed the lungs in the open thorax while controlling airway pressure. Using a cryosample preparation chamber attached to a scanning electron microscope equipped with a low temperature stage, we in vacuo freeze‐fractured the lung, gold coated the fractured surface and used secondary electron emission scanning electron microscopy to examine the frozen‐hydrated lung with scanning electron micrographs of freeze‐dried and airway fixed, critical point dried lung. We discuss the advantages of frozen‐hydrated scanning lung preservation for pulmonary edema research, especially in regard to quantifying alveolar fluid distribution by stereo photogrammetry, and suggest areas of future research to improve the method.
Lateral beam stability of a computer assisted scanning electron microscope / x‐ray microanalysis system
Authors: Wurster R. , Lehner S.
Published: August 2011

Digital 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

New 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

A 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

Microscopic 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

The 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

Delicate 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

The 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.
Theoretical aspects of intensity gradient analysis
Authors: Smart P. , Tovey N. K.
Published: August 2011

The correct choice of formulae for intensity gradient analysis depends on noise and resolution, economy and accuracy, and the shape (square, rectangular, hexagonal, or other) of rasters used. A method of finding appropriate formulae is given.
Iron‐polyethylene glycol impregnation: An attempt to reduce shrinkage of specimens in SEM preparation
Authors: Ohtsuka A. , Murakami T.
Published: August 2011

Glutaraldehyde‐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

Nondestructive 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

X‐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

Charging 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

The 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

Mott 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

Results 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

Computer‐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

The 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

Three 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

We 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

The 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.
Feature‐based image reconstruction in three dimensions for electron microscopy Part 2: Image reconstruction
Authors: Hood P. J. , Howitt D. G.
Published: August 2011

The three‐dimensional reconstruction of an electron microscopy specimen from a feature‐based representation of the images taken from it is described. The method involves the assembling of the features, their correlation, and the measurement of the disparities between the original images.
Analysis of an altered simple silicate glass using different mineral and glass standards
Authors: Mazer J. J. , Bates J. K.
Published: August 2011

Quantitative 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

A 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

Modern 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

A 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.
Monte Carlo simulation of CL and EBIC contrasts for isolated dislocations
Authors: Czyżewski Z. , Joy D. C.
Published: August 2011

Electron beam‐induced current (EBIC) and cathodoluminescence (CL) are widely used to investigate semiconductor materials and devices, particularly to obtain information on the recombination properties and the geometry of defects. This report describes a simple formulation of CL and EBIC contrasts based on the Born approximation of excess carrier density in the presence of a pointlike defect. Quantitative interpretation of the CL and EBIC images is often difficult because of a lack of accurate theory treating simultaneously both the details of the electron beam penetration in the semiconductor and the generation of EBIC and CL signals. To overcome this difficulty, the Monte Carlo approach to the phenomenon of the electron beam penetration in solids has been developed to calculate the CL and EBIC signals during a simulation of the electron trajectory. Results for an inclined dislocation in GaAs are presented.
Calculation and comparison of the surface ionization ϕ(0)
Authors: August H‐J. , Wernisch J.
Published: August 2011

An analytical expression for the surface ionization ϕ(O) is derived from fundamentals, viz., the ionization cross section and the angular and energy distribution of backscattered electrons. In order to avoid numerical integrations, a simple formula for the energy distribution of backscattered electrons is presented. The values given by the resulting expression for ϕ(O) are compared with those given by already known formulae and with experimental findings. In general, the agreement is quite satisfactory, although the calculated values generally are smaller than those experimentally found, especially at high overvoltages. This can at least partly be explained by secondary fluorescence excited by the continuous radiation, of which the correction has not been taken into account in the experimental determination of the ϕ(O) values.
Design and construction of an environmental SEM (part 4)
Authors: Danilatos G. D.
Published: August 2011

A new detection configuration using the gaseous detector device in the environmental scanning electron microscope (ESEM) is demonstrated. First, the pressure‐limiting aperture (PLA1) is used simultaneously as a biased electrode to collect the ionization current produced in the gaseous environment of the microscope. Second, a wire electrode is placed above the pressure‐limiting aperture, and it is shown that enough signal from the specimen escapes through the aperture to produce satisfactory images. These detection configurations allow the use of high specimen chamber pressures.
Atomic scale morphology of the surface of the crystalline Si formed by ion etching
Authors: Song M. , Hashimoto H. , Yokota Y. , Awaji M.
Published: August 2011

The atomic scale structure of the ion‐etched Si surface parallel to (111) and (100) was investigated by transmission electron microscopy (TEM). The cross‐sectional high‐resolution TEM observation of the etched surfaces revealed that the 100 surface consists of small protuberances surrounded by (111) planes smaller than 10 nm, and the 111 surface consists of atomically flat surfaces accompanying small fragments with atomic chain structure both on the surface and in the amorphous layer covering the etched surface.
Size effects in glass fragment identification by micro‐x‐ray fluorescence analysis
Authors: Pozsgai I. , Barna A. , Toth P.
Published: August 2011

Energy‐dispersive x‐ray fluorescence (EDXRF) analysis with a lateral resolution of 300 μm has been used in scanning electron microscopy to carry out model experiments for the identification of small glass fragments. Small sample dimensions can produce size effects which cause intensity changes in the EDXRF spectra as compared with bulk specimen spectra. These effects can be analysed by means of the inelastically scattered Mo Kα source line as long as the x‐ray spot size is smaller than the specimen dimension.
Surface investigations with a combined scanning electron–scanning tunneling microscope
Authors: Fuchs H. , Laschinski R.
Published: August 2011

We have combined a scanning tunneling microscope (STM) with a scanning electron microscope (SEM) for surface investigations of atomically flat surfaces, ultrathin adsorbate films, and material surfaces. The mechanical stability of the hybrid instrument allows high‐resolution SEM of samples mounted on the STM stage and atomic resolution with the STM. Experimental results of combined SEM/STM investigations on textured material surfaces, submicron structures, and atomically flat conducting surfaces are presented. An example is given for surface machining with the STM under SEM control.
Calibration of SEM voltage using electron channeling patterns of silicon
Authors: Kozubowski J. A. , Keller R. , Gerberich W. W.
Published: August 2011

The actual accelerating voltage in a scanning electron microscope (SEM) was determined using electron channeling patterns (ECPs). The technique involves selection of a set of high index lines. The properly chosen set of lines exhibits highly sensitive shifts as voltage is changed, allowing rapid SEM voltage calibration. The actual voltage is determined from a simple formula involving measurement of two distances on an ECP obtained from (100) silicon. Such calibrations were performed using both (100)Si and (100)GaAs crystals and the results were compared with voltage estimates from the high energy end of the continuous x‐ray spectrum from silicon. The ECP determination was accurate to about 0.1 keV for a nominal setting of 15 keV. This is comparable to the accuracy of the x‐ray technique when short (∼300 s) counting times are used.
Mapping mineralogy distribution and abundance in rock samples by scanning Fourier transform infrared microscopy
Authors: Liang K. K. , Supp M. , Murphy W. F.
Published: August 2011

Scanning Fourier transform infrared microscopy (SFTIRM) provides a nondestructive, automated technique that gives both spatial and quantitative description of mineralogy in rocks on a microscopic scale. SFTIRM is essentially a combination of Fourier transform infrared spectroscopy and scanning microscopy. This report describes and demonstrates the principle and operation of the technique. Mineral identification is based on specular reflectance spectra collected in the midinfrared. Mineral abundances are extracted by two different spectral fitting algorithms: least‐mean‐squares (LMS) and linear area fitting (LAF). A sedimentary rock composed mostly of dolomite, some quartz, and finely layered illite is imaged. The SFTIRM images clearly show the spatial distribution and abundance variations of the minerals.