Detection of a point defect in a silicon single crystal by high-resolution TEM

1995 ◽  
Vol 53 ◽  
pp. 466-467
Author(s):  
M. Awaji
Keyword(s):  
High Resolution ◽  
Single Crystal ◽  
Point Defect ◽  
Point Defects ◽  
Noise Level ◽  
Dark Field ◽  
Silicon Single Crystal ◽  
High Resolution Image ◽  
Dark Field Imaging ◽  
Field Imaging

It is necessary to improve the resolution, brightness and signal-to-noise ratio(s/n) for the detection and identification of point defects in crystals. In order to observe point defects, multi-beam dark-field imaging is one of the useful methods. Though this method can improve resolution and brightness compared with dark-field imaging by diffuse scattering, the problem of s/n still exists. In order to improve the exposure time due to the low intensity of the dark-field image and the low resolution, we discuss in this paper the bright-field high-resolution image and the corresponding subtracted image with reference to a changing noise level, and examine the possibility for in-situ observation, identification and detection of the movement of a point defect produced in the early stage of damage process by high energy electron bombardment.The high-resolution image contrast of a silicon single crystal in the [10] orientation containing a triple divacancy cluster is calculated using the Cowley-Moodie dynamical theory and for a changing gaussian noise level. This divacancy model was deduced from experimental results obtained by electron spin resonance. The calculation condition was for the lMeV Berkeley ARM operated at 800KeV.

A Preparation of High Resolution Standards for Electron Microscopy. Part II

1971 ◽  
Vol 29 ◽  
pp. 160-161
Author(s):  
Akira Tanaka ◽  
David F. Harling
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Carbon Black ◽  
Single Crystal ◽  
Dark Field ◽  
Graphitized Carbon Black ◽  
Graphitized Carbon ◽  
Dark Field Imaging ◽  
Crystal Films ◽  
Micro Holes

In the previous paper, the author reported on a technique for preparing vapor-deposited single crystal films as high resolution standards for electron microscopy. The present paper is intended to describe the preparation of several high resolution standards for dark field microscopy and also to mention some results obtained from these studies. Three preparations were used initially: 1.) Graphitized carbon black, 2.) Epitaxially grown particles of different metals prepared by vapor deposition, and 3.) Particles grown epitaxially on the edge of micro-holes formed in a gold single crystal film.The authors successfully obtained dark field micrographs demonstrating the 3.4Å lattice spacing of graphitized carbon black and the Au single crystal (111) lattice of 2.35Å. The latter spacing is especially suitable for dark field imaging because of its preparation, as in 3.), above. After the deposited film of Au (001) orientation is prepared at 400°C the substrate temperature is raised, resulting in the formation of many square micro-holes caused by partial evaporation of the Au film.

Reflection Electron Microscopy

1975 ◽  
Vol 33 ◽  
pp. 122-123
Author(s):  
P. E. Højlund Nielsen ◽  
J. M. Cowley
Keyword(s):  
Electron Microscopy ◽  
Single Crystal ◽  
Chromatic Aberration ◽  
Dark Field ◽  
Energy Spread ◽  
Crystal Surfaces ◽  
Single Crystal Surfaces ◽  
Dark Field Imaging ◽  
Reflection Electron Microscopy ◽  
Field Imaging

Reflection electron microscopy was widely used before 1960 for the study of surfaces. For the imaging diffuse scattered electrons was applied. For avoiding a severe foreshortening the surface was illuminated and viewed at fairly large angles. That resulted in a large energy spread of the scattered electrons so the resolution was limited to about 500Å due to chromatic aberration. Since such a resolution could be achieved more readily in scanning microscopes, the method was abandoned. However for single crystal surfaces the situation is entirely different. If the surface can be maintained reasonably clean, strong diffraction spots can be obtained and the energy spread in the diffracted beam is usually small; thus the imaging of the surface can be performed in a manner similar to the dark field imaging of a thin crystalline specimen.

Imaging of III-V Compound Superlattices by Hrem and Rem

1986 ◽  
Vol 77 ◽  
Author(s):  
B. C. De Cooman ◽  
J. R. Conner ◽  
S. R. Summerfelt ◽  
S. McKernan ◽  
C. B. Carter ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Dark Field ◽  
Contrast Effects ◽  
Cross Sectional ◽  
Dark Field Imaging ◽  
Thin Foils ◽  
High Resolution Tem ◽  
Reflection Electron Microscopy ◽  
Field Imaging

ABSTRACTTwo techniques for the analysis of III-V compound superlattices are examined. It has been proposed that high-resolution TEM of [100]-oriented thin foils would give an improvement in layer contrast compared with [110]-oriented thin foils; it is shown here that the contrast of [100]-oriented superlattices is not necessarily better. Moreover, both high resolution and conventional dark-field imaging may be subject to significant diffraction contrast effects resulting from the bending of the reflecting planes near the surface of the sample. Reflection electron microscopy (REM) of cross-sectional (110) cleavage planes can also yield dark-field superlattice images and selected area RHEED patterns can in principle be used to determine reliably the superlattice strain as surface effects are minimized.

Combined Analytical And High Resolution Microscopy - A Case Study

1977 ◽  
Vol 35 ◽  
pp. 146-147
Author(s):  
R. H. Geiss ◽  
D. R. Clarke
Keyword(s):  
High Resolution ◽  
Rapid Development ◽  
Dark Field ◽  
Minor Phase ◽  
X Ray ◽  
Dark Field Imaging ◽  
Field Imaging ◽  
High Resolution Microscopy ◽  
Comprehensive Characterization

The rapid development of n ew metallic and ceramic alloys is making greater demands of our materials characterisation techniques and increasingly when looking at a microstructure we need to know the answers to the following types of questions: a) what are the crystal structures of the constituent phases and inclusions?; b) what are their elemental compositions?; c) is that minor phase crystalline or amorphous?; d) has an element segregated? What is more we need to know this information from all the phases, even the very smallest. Hot-pressed silicon nitride fluxed with yttrium oxide is an example of a newly developed material and we have used it as a case study to determine the capabilities of commercially available equipment for materials characterization. Specifically, we have used a combination of rocking beam micro-diffraction, high resolution dark field imaging, x-ray microanalysis, lattice fringe imaging and D stereo-microscopy to investigate the material. The results of such a comprehensive characterization and the limitations experienced will be described in the presentation.

Si(111)-(5x2) Au structure from off-axis high-resolution Transmission Electron Microscopy

1994 ◽  
Vol 52 ◽  
pp. 762-763
Author(s):  
R. Plass ◽  
L. D. Marks
Keyword(s):  
High Resolution ◽  
Semiconductor Device ◽  
Dark Field ◽  
X Ray Diffraction ◽  
Plan View ◽  
Flat Surfaces ◽  
Dark Field Imaging ◽  
Semiconductor Interfaces ◽  
Transmission Electron ◽  
Field Imaging

Although metal semiconductor interfaces play a major role in semiconductor device performance the basic understanding of the atomic structure of many of these interfaces has been elusive. The submonolayer of gold on silicon (111) system is of special interest as it displays several different surface structures depending on gold coverage and temperature. Substantial light has been shed on one of these structures, the 5×2 present between .1 and .5 gold monolayers, in recent x-ray diffraction and high resolution STM studies, yet the placement of the gold atoms remains unclear. We present here a solution for this structure found using off-axis plan view HREM and digital image restoration in combination with more conventional bright-field, dark-field imaging and diffraction techniques.Instrumental details related to this experiment have been reviewed by Bonevich and Marks. Si 111 oriented TEM samples with clean, fairly flat surfaces were prepared using Ar+ ion sputter/electron beam annealing cycles.

Quantitative compositional mapping of InxGa1-XAs/GaAs quantum wells by annular dark field imaging

1995 ◽  
Vol 53 ◽  
pp. 294-295
Author(s):  
S. Hillyard ◽  
Y.-P. Chen ◽  
W.J. Schaff ◽  
L.F. Eastman ◽  
J. Silcox
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Quantum Wells ◽  
Transmission Electron Microscope ◽  
Dark Field ◽  
Thickness Variation ◽  
Dark Field Imaging ◽  
Transmission Electron ◽  
Annular Dark Field ◽  
Field Imaging

Annular dark field imaging in the scanning transmission electron microscope (STEM) exhibits both high resolution and Z-contrast. It is intrinsically quantitative since image data can be recorded directly from linear detectors into digital memory. Annular dark field imaging has been used, along with energy filtered imaging to correct for sample thickness variation, to map out the In concentration in InxGa1-xAs quantum wells with near atomic resolution and sensitivity. This approach is similar to “chemical lattice imaging”, which maps out composition variation using a conventional transmission electron microscope image and a vector pattern recognition algorithm.The quantum wells were grown by molecular-beam epitaxy (MBE). Figure 1 shows a typical high resolution annular dark field image of a 50 Å wide nominal In0.3Ga0.7As/GaAs quantum well. The linescan in figure 2 gives the actual numbers making up the image. Barring contaminants and lattice imperfections, the change in intensity with position is caused by two things: variation of In concentration and thickness.

Origin of Threefold Periodicity in High-Resolution Transmission Electron Microscopy Images of Thin Film Cubic SiC

1999 ◽  
Vol 5 (6) ◽  
pp. 420-427 ◽  
Author(s):  
U. Kaiser ◽  
A. Chuvilin ◽  
P.D. Brown ◽  
W. Richter
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Molecular Beam ◽  
Dark Field ◽  
Dark Field Imaging ◽  
Transmission Electron ◽  
Field Imaging ◽  
Microscopy Images ◽  
Image Simulations

Abstract: High-resolution transmission electron microscopy (HRTEM) images of the [1–10] zone of cubic SiC layers grown by molecular beam epitaxy (MBE) often reveal regions of material exhibiting an unusual threefold periodicity. The same contrast was found in earlier works of Jepps and Page, who attributed this contrast in HRTEM images of polycrystalline SiC to the 9R-SiC polytype. In this report we demonstrate by HRTEM image simulations that the model of the 9R polytype and an alternative twinning model can fit qualitatively the experimental HRTEM images. However, by comparing the fast Fourier transform (FFT) patterns of the experiments and the simulations, as well as by using dark-field imaging, we show unambiguously that only the model of overlapping twinned 3C-SiC crystals fully agrees with the experiments.

scholarly journals White Beam Differential Phase and Dark Field Imaging at High Resolution

2018 ◽  
Vol 24 (S2) ◽  
pp. 158-161
Author(s):  
M Endrizzi ◽  
GK Kallon ◽  
L Brombal ◽  
D Dreossi ◽  
A Olivo
Keyword(s):  
High Resolution ◽  
Dark Field ◽  
Differential Phase ◽  
Dark Field Imaging ◽  
White Beam ◽  
Field Imaging

High-resolution dark-field imaging in epoxy and polyimide systems

1982 ◽  
Vol 20 (4) ◽  
pp. 579-591 ◽  
Author(s):  
A. Oberlin ◽  
J. Ayache ◽  
M. Oberlin ◽  
M. Guigon
Keyword(s):  
High Resolution ◽  
Dark Field ◽  
Dark Field Imaging ◽  
Field Imaging
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