High Resolution Transmission Electron Microscopy Investigation of the Defect Structure in CdMnTe Layers Grown on GaAs by MOCVD

1987 ◽  
Vol 102 ◽  
Author(s):  
J. H. Mazur ◽  
P. Grodzinski ◽  
A. Nouhi ◽  
R. J. Stirn
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Substrate Surface ◽  
Chemical Vapor ◽  
High Resolution Electron Microscopy ◽  
Organic Chemical ◽  
Orientation Relationships ◽  
Transmission Electron ◽  
Microscopy Investigation ◽  
Resolution Electron

ABSTRACTElectron diffraction and high resolution electron microscopy were used for analysis of Cd1−xMnxTe films grown on (100)2°[011] GaAs substrates by metal organic chemical vapor deposition (MOCVD) at 420°C (x=O.3) and 450°C (x=0.5). It has been found that these two conditions produce dramatically different microstructures. Two orientation relationships of the epilayers with respect to the substrate were observed. It is suggested that this phenomenon may be related to GaAs substrate surface morphology.

Heteroepitaxial Diamond Formed on Silicon Wafer Observed by High Resolution Electron Microscopy

1994 ◽  
Vol 357 ◽  
Author(s):  
Jie Yang ◽  
Zhangda Lin ◽  
Li-Xin Wang ◽  
Sing Jin ◽  
Ze Zhang
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Diamond Films ◽  
Chemical Vapor ◽  
High Resolution Electron Microscopy ◽  
Cross Sectional ◽  
Diamond Crystals ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Hot Filament

AbstractDiamond films with high preferential orientation (111) on silicon (100) crystalline orientation substrates had been obtained by hot-filament chemical vapor deposition (HFCVD) method. X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, and high-resolution cross-sectional transmission electron microscopy (HREM) are used to characterizate the structure and morphology of the synthesised diamond films. Diamond (111) plans had been local grown epitaxially on the Si(100) substrate observed by HREM. SEM photographes show that plane diamond crystals have been obtained.

Structural properties of epitaxial TiO2 films grown on sapphire (11$\overline 1$0) by MOCVD

1992 ◽  
Vol 7 (9) ◽  
pp. 2495-2506 ◽  
Author(s):  
H.L.M. Chang ◽  
H. You ◽  
Y. Gao ◽  
J. Guo ◽  
C.M. Foster ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Structural Properties ◽  
Growth Temperature ◽  
Substrate Surface ◽  
Chemical Vapor ◽  
High Resolution Electron Microscopy ◽  
Organic Chemical ◽  
Resolution Electron ◽  
Titanium Dioxide Thin Films ◽  
Deposited Films

Titanium dioxide thin films were grown on sapphire (11$\overline 1$0) substrates in a low-pressure metal-organic chemical vapor deposition system at temperatures ranging from 400 to 800 °C. Raman scattering, x-ray diffraction, transmission electron microscopy, and high resolution electron microscopy techniques were employed to characterize the structural properties of the deposited films. The resultant phases and structures of the deposited films depended on both the growth temperature and the substrate surface properties (surface imperfections, steps, etc.). At the growth temperature of 800 °C, single-crystal rutile films were obtained reproducibly with two possible epitaxial relationships. At lower temperatures (400 to 775 °C), the deposited films can be epitaxial or polycrystalline with highly oriented grains. The similarity between the atomic arrangements of the substrate and the film is discussed in detail to explain the observed epitaxial relationships and abruptness of the interfaces.

High-Resolution Electron Microscopy of Interfaces In Ain - Braze Metal Alloy Systems

1989 ◽  
Vol 159 ◽  
Author(s):  
A. H. Carim
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
High Resolution Electron Microscopy ◽  
Nitride Phase ◽  
Orientation Relationships ◽  
Transmission Electron ◽  
Resolution Electron ◽  
High Resolution Images ◽  
Lattice Planes ◽  
Specific Orientation

ABSTRACTThe microstructural aspects of active brazing of AIN with a Ag-Cu-Ti alloy have been investigated. A series of reaction product layers are formed. TiN is produced in contact with the polycrystalline, bulk AIN. High-resolution transmission electron microscopy and microdiffraction demonstrate that some of the TiN grains at the interface display specific orientation relationships with respect to the adjoining AIN crystallites. As has sometimes been observed in studies of epitaxy in other systems, these relationships are not necessarily those that provide the minimum geometrical mismatch between one or more sets of lattice planes. Farther from the substrate, an fl-type nitride phase with composition (Ti,Cu,Al)6N occurs as a reaction product. High-resolution images confirm the absence of amorphous or crystalline intervening phases at the TiN-ŋ interface and at ŋ grain boundaries.

High Resolution Transmission Electron Microscopy of an automobile catalytic converter

1990 ◽  
Vol 48 (4) ◽  
pp. 242-243
Author(s):  
Jan-Olle Malm ◽  
Jan-Olov Bovin
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Catalytic Converter ◽  
Active Material ◽  
Image Intensifier ◽  
High Resolution Electron Microscopy ◽  
Detailed Knowledge ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Atomic Surface

Understanding of catalytic processes requires detailed knowledge of the catalyst. As heterogeneous catalysis is a surface phenomena the understanding of the atomic surface structure of both the active material and the support material is of utmost importance. This work is a high resolution electron microscopy (HREM) study of different phases found in a used automobile catalytic converter.The high resolution micrographs were obtained with a JEM-4000EX working with a structural resolution better than 0.17 nm and equipped with a Gatan 622 TV-camera with an image intensifier. Some work (e.g. EDS-analysis and diffraction) was done with a JEM-2000FX equipped with a Link AN10000 EDX spectrometer. The catalytic converter in this study has been used under normal driving conditions for several years and has also been poisoned by using leaded fuel. To prepare the sample, parts of the monolith were crushed, dispersed in methanol and a drop of the dispersion was placed on the holey carbon grid.

X-Ray-Optical Multilayer Structures Studied Using High Resolution Electron Microscopy.

1986 ◽  
Vol 77 ◽  
Author(s):  
Mary Beth Stearns ◽  
Amanda K. Petford-Long ◽  
C.-H. Chang ◽  
D. G. Stearns ◽  
N. M. Ceglio ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Substrate Surface ◽  
High Resolution Electron Microscopy ◽  
Atomic Scale ◽  
Degree Of Crystallinity ◽  
Multilayer Systems ◽  
Layer Width ◽  
X Ray ◽  
Resolution Electron

ABSTRACTThe technique of high resolution electron microscopy has been used to examine the structure of several multilayer systems (MLS) on an atomic scale. Mo/Si multilayers, in use in a number of x-ray optical element applications, and Mo/Si multilayers, of interest because of their magnetic properties, have been imaged in cross-section. Layer thicknesses, flatness and smoothness have been analysed: the layer width can vary by up to 0.6nm from the average value, and the layer flatness depends on the quality of the substrate surface for amorphous MLS, and on the details of the crystalline growth for the crystalline materials. The degree of crystallinity and the crystal orientation within the layers have also been investigated. In both cases, the high-Z layers are predominantly crystalline and the Si layers appear amorphous. Amorphous interfacial regions are visible between the Mo and Si layers, and crystalline cobalt suicide interfacial regions between the Co and Si layers. Using the structural measurements obtained from the HREM results, theoretical x-ray reflectivity behaviour has been calculated. It fits the experimental data very well.

Structure of InAs Quantum Dots in Si Matrix Investigated by High Resolution Electron Microscopy

1999 ◽  
Vol 571 ◽  
Author(s):  
N. D. Zakharov ◽  
P. Werner ◽  
V. M. Ustinov ◽  
A.R. Kovsh ◽  
G. E. Cirlin ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Critical Thickness ◽  
High Resolution Electron Microscopy ◽  
Geometrical Parameters ◽  
Inas Quantum Dots ◽  
Temperature Growth ◽  
Transmission Electron ◽  
Resolution Electron

ABSTRACTQuantum dot structures containing 2 and 7 layers of small coherent InAs clusters embedded into a Si single crystal matrix were grown by MBE. The structure of these clusters was investigated by high resolution transmission electron microscopy. The crystallographic quality of the structure severely depends on the substrate temperature, growth sequence, and the geometrical parameters of the sample. The investigation demonstrates that Si can incorporate a limited volume of InAs in a form of small coherent clusters about 3 nm in diameter. If the deposited InAs layer exceeds a critical thickness, large dislocated InAs precipitates are formed during Si overgrowth accumulating the excess of InAs.

Silicon-Sapphire Interface: A High Resolution Electron Microscopy Study

1980 ◽  
Vol 2 ◽  
Author(s):  
Fernando A. Ponce
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Silicon Layer ◽  
High Resolution Electron Microscopy ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Resolution Limit ◽  
High Concentration ◽  
Transmission Electron ◽  
Resolution Electron

ABSTRACTThe structure of the silicon-sapphire interface of CVD silicon on a (1102) sapphire substrate has been studied in crøss section by high resolution transmission electron microscopy. Multibeam images of the interface region have been obtained where both the silicon and sapphire lattices are directly resolved. The interface is observed to be planar and abrupt to the instrument resolution limit of 3 Å. No interfacial phase is evident. Defects are inhomogeneously distributed at the interface: relatively defect-free regions are observed in the silicon layer in addition to regions with high concentration of defects.

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