Transmission Electron Microscopy of II-VI/III-V Semiconductor Heteroepitaxial Interfaces

1989 ◽  
Vol 161 ◽  
Author(s):  
D. Li ◽  
N. Otsuka ◽  
J. Qiu ◽  
J. Glenn ◽  
M. Kobayashi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Molecular Beam ◽  
Dark Field ◽  
Group Iii ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Microscope Images ◽  
High Resolution Electron Microscope

ABSTRACTInterfaces of pseudomorphic (100)ZnSe/GaAs and (100)CdTe/InSb heterostructures grown by molecular beam epitaxy have been studied by transmission electron microscopy. High resolution electron microscope images show dark bands with thicknesses of one or two monolayers at the interfaces. The interfaces appear as bright lines in dark field images of the 200 type reflections, while they become dark lines in dark field images of the 400 type reflections. These observations are explained by assuming the existence of interfaces layers of III2VI3 compounds which have structural vacancies in the sublattices of the group III atoms.

300kv high-performance analytical TEM (H-9000)

1987 ◽  
Vol 45 ◽  
pp. 108-109
Author(s):  
H. Kobayashi ◽  
H. Sato ◽  
K. Miyauchi ◽  
T. Onai ◽  
K. Shii ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
High Performance ◽  
Image Resolution ◽  
X Ray ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Analytical Microscopy ◽  
High Resolution Electron Microscope

Higher voltage operation has many advantages for transmission electron microscopy.These advantages include better TEM image resolution and ease of specimen imaging. For analytical microscopy, the higher voltage operation has advantages such as higher source brightness, and better spatial resolution.We reported development of a 300kV ultra high resolution electron microscope. At this time, we would like to report an analytical type 300kV electron microscope.We have incorporated a side entry specimen stage which permits ±45° specimen tilt and is convenient for characteristic x-ray detection. We have also incorporated an analytical objective polepiece which has Cs of 2. 5mm, Cc of 2. 3mm and theoretical TEM image resolution of 0.23nm.

Strain in Coherent Ge Quantum Islands on Si Measured by Transmission Electron Microscopy

1999 ◽  
Vol 571 ◽  
Author(s):  
Chuan-Pu Liu ◽  
Peter D. Miller ◽  
William L. Henstrom ◽  
J. Murray Gibson
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Quantitative Method ◽  
Dark Field ◽  
Small Islands ◽  
Transmission Electron

ABSTRACTWe describe a quantitative method for measuring the strain in small islands, and show results for coherent Ge islands on Si. The method uses dark field images from backside thinned samples in the transmission electron microscope. We show that no independent strain models are needed in the measurement, which employs an excellent “abrupt displacement” approximation. Results show that the strain in Ge domes is higher than in pyramids as expected.

Investigation of the microstructure of hetero-epitaxial Si/CoSi2/Si (001) and (111) structures by TEM

1990 ◽  
Vol 48 (4) ◽  
pp. 386-387
Author(s):  
C.W.T. Bulle-Lieuwma ◽  
A.H. van Ommen
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
High Resolution Electron Microscopy ◽  
High Dose ◽  
Metal Base ◽  
Si Substrates ◽  
Transmission Electron ◽  
Resolution Electron ◽  
High Dose Implantation

Hetero-epitaxial Si/CoSi2/Si structures have been formed by high dose implantation of Co+ ions into (001) and (111) Si substrates and subsequent annealing of the substrates. Such structures are of interest due to their application as metal base base and permeable base transistors. We have studied the microstructure of both as-implanted and annealed structures by transmission electron microscopy (TEM), including high-resolution electron microscopy (HREM). HREM was performed using a Philips 300 kV electron microscope with a point resolution of approximately 0.19 nm. CoSi2 layers have been formed by implantation of 170 keV Co+ ions at a temperature of 450°C and to doses of 1× 1017 and 2× 1017 Co+ / cm2. The wafers were annealed for 30 minutes in a N2/H2 ambient at a temperature of 1000°C. In the as implanted structures, the Co is present in the form of epitaxial CoSi2 precipitates. Precipitates occur both in an aligned (A-type) and twinned (B-type) orientation. Annealing of the implanted structures results in the formation of a buried CoSi2 layer of aligned orientation. A striking observation is that the CoSi2 layer has an aligned orientation with respect to the Si matrix, whereas CoSi2 grown on top of (111) Si has a twinned orientation. The mechanism behind this phenomenon is not fully understood. We think that geometrical aspects play a crucial role. Therefore we have studied in detail the geometry of the coordination of coherent CoSi2 precipitates.

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.

Transmission Electron Microscope Study of An Ordered Structure in GaAs0.5 Sb0.5 Grown By Molecular Beam Epitaxy

1987 ◽  
Vol 102 ◽  
Author(s):  
Y. E. Ihm ◽  
N. Otsuka ◽  
Y. Hirotsu ◽  
J. Klem ◽  
H. Morkoc
Keyword(s):  
Electron Microscopy ◽  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
High Resolution Electron Microscopy ◽  
Dark Field ◽  
Ordered Structure ◽  
Domain Structures ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Diffraction Patterns

ABSTRACTThe ordered structure in a (100) GaAs0.5 Sb0.5 epilayer grown by molecular beam epitaxy has been studied by transmission electron microscopy. Domain structures are observed in dark field images of superstructure reflections. The ordered structure is derived by the analysis of diffraction patterns taken from single domains. The ordered structure is described as an alternate stacking of As and Sb planes in the <111> direction of the FCC sublattice. The alternate stacking of As and Sb plane is directly observed by high resolution electron microscopy.

Electron microscopy and diffraction studies of polyimides

1983 ◽  
Vol 41 ◽  
pp. 28-29
Author(s):  
O.C. de Hodgins ◽  
K. R. Lawless ◽  
R. Anderson
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Structural Features ◽  
Inert Atmosphere ◽  
Polyimide Films ◽  
Resolution Electron ◽  
The Matrix ◽  
High Resolution Electron Microscope ◽  
Diffraction Patterns ◽  
Polymeric Samples

Commercial polyimide films have shown to be homogeneous on a scale of 5 to 200 nm. The observation of Skybond (SKB) 705 and PI5878 was carried out by using a Philips 400, 120 KeV STEM. The objective was to elucidate the structural features of the polymeric samples. The specimens were spun and cured at stepped temperatures in an inert atmosphere and cooled slowly for eight hours. TEM micrographs showed heterogeneities (or nodular structures) generally on a scale of 100 nm for PI5878 and approximately 40 nm for SKB 705, present in large volume fractions of both specimens. See Figures 1 and 2. It is possible that the nodulus observed may be associated with surface effects and the structure of the polymers be regarded as random amorphous arrays. Diffraction patterns of the matrix and the nodular areas showed different amorphous ring patterns in both materials. The specimens were viewed in both bright and dark fields using a high resolution electron microscope which provided magnifications of 100,000X or more on the photographic plates if desired.

Phenomena Associated with Oxygen in Titanium

1967 ◽  
Vol 25 ◽  
pp. 310-311
Author(s):  
E. U. Lee ◽  
P. A. Garner ◽  
J. S. Owens
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Microstructural Changes ◽  
Electrolytic Polishing ◽  
Interstitial Impurities ◽  
Thin Foils ◽  
Transmission Electron ◽  
Iodide Titanium ◽  
Alpha Titanium

Evidence for ordering (1-6) of interstitial impurities (O and C) has been obtained in b.c.c. metals, such as niobium and tantalum. In this paper we report the atomic and microstructural changes in an oxygenated c.p.h. metal (alpha titanium) as observed by transmission electron microscopy and diffraction.Oxygen was introduced into zone-refined iodide titanium sheets of 0.005 in. thickness in an atmosphere of oxygen and argon at 650°C, homogenized at 800°C and furnace-cooled in argon. Subsequently, thin foils were prepared by electrolytic polishing and examined in a JEM-7 electron microscope, operated at 100 KV.

The 1-MeV Electron Microscope Installation at the University of Colorado

1973 ◽  
Vol 31 ◽  
pp. 8-9 ◽  
Author(s):  
Mircea Fotino
Keyword(s):  
Electron Microscopy ◽  
Developmental Biology ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
National Institutes Of Health ◽  
Experimental Program ◽  
University Of Colorado ◽  
Transmission Electron ◽  
The University ◽  
Research Resources

A new 1-MeV transmission electron microscope (Model JEM-1000) was installed at the Department of Molecular, Cellular and Developmental Biology of the University of Colorado in Boulder during the summer and fall of 1972 under the sponsorship of the Division of Research Resources of the National Institutes of Health. The installation was completed in October, 1972. It is installed primarily for the study of biological materials without many of the limitations hitherto unavoidable in standard transmission electron microscopy. Only the technical characteristics of the installation are briefly reviewed here. A more detailed discussion of the experimental program under way is being published elsewhere.

Simulation of three Dimensional Defect Images in Transmission Electron Microscopy

1976 ◽  
Vol 34 ◽  
pp. 470-471
Author(s):  
W. D. Cooper ◽  
C. S. Hartley ◽  
J. J. Hren
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Three Dimensional ◽  
Crystalline Lattice ◽  
Continuum Models ◽  
Thin Foils ◽  
Transmission Electron ◽  
Microscope Images ◽  
General Computer Program ◽  
General Computer

Interpretation of electron microscope images of crystalline lattice defects can be greatly aided by computer simulation of theoretical contrast from continuum models of such defects in thin foils. Several computer programs exist at the present time, but none are sufficiently general to permit their use as an aid in the identification of the range of defect types encountered in electron microscopy. This paper presents progress in the development of a more general computer program for this purpose which eliminates a number of restrictions contained in other programs. In particular, the program permits a variety of foil geometries and defect types to be simulated.The conventional approximation of non-interacting columns is employed for evaluation of the two-beam dynamical scattering equations by a piecewise solution of the Howie-Whelan equations.

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