scholarly journals Characterization of Gaas/Si/GaAs Heterointerfaces

1989 ◽  
Vol 148 ◽  
Author(s):  
Zuzanna Liliental-Weber ◽  
Raymond P. Mariella
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Low Temperature ◽  
Defect Density ◽  
Si Substrate ◽  
Reverse Polarity ◽  
Si Substrates ◽  
Transmission Electron ◽  
Metal Semiconductor Metal

ABSTRACTTransmission electron microscopy of GaAs grown on Si for metal-semiconductor-metal photodetectors is presented in this paper. Two kinds of samples are compared: GaAs grown on a 15 Å Si epilayer grown on GaAs, and GaAs grown at low temperature (300°C) on Si substrates. It is shown that the GaAs epitaxial layer grown on thin Si layer has reverse polarity to the substrate (antiphase relation). Higher defect density is observed for GaAs grown on Si substrate. This higher defect density correlates with an increased device speed, but with reduced sensitivity.

LOW-Temperature Epitaxial Growth of GaAs on Si Substrates by MBE

1992 ◽  
Vol 263 ◽  
Author(s):  
Ting-Yen Chiang ◽  
En-Huery Liu ◽  
Der-Hwa Yiin ◽  
Tri-Rung Yew
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Low Temperature ◽  
Epitaxial Growth ◽  
Defect Density ◽  
Solution Treatment ◽  
Plan View ◽  
Si Substrates ◽  
Gaas On Si ◽  
Transmission Electron

ABSTRACTThis paper presents results of the low—temperature epitaxial growth of GaAs on Si substrates with orientation 1°—4° off (100) by molecular beam epitaxy (MBE). The epitaxial growth ·is carried out on Si wafers subjected to HF solution treatment by “spin-etch” technique before the wafer is transferred to the entry chamber of MBE system. Methods used for reducing defect density in the epitaxial layers are proposed. The characterization techniques include cross-sectional transmission electron microscopy (XTEM), plan-view transmission electron microscopy, scanning electron microscopy (S EM), and double crystal X-ray diffraction (DCXRD). Epitaxial films with a full width at half—maximum (FWHM) of about 310 arcsec measured by DCXRD are obtained without annealing.-

Structural Characterization of Nc-Si/A-Sio2 Superlattices Subjected To Thermal Treatment

1998 ◽  
Vol 536 ◽  
Author(s):  
G. F. Grom ◽  
L. Tsybeskov ◽  
K. D. Hirschman ◽  
P. M. Fauchet ◽  
J. P. McCaffrey ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Raman Spectroscopy ◽  
Defect Density ◽  
High Temperature Annealing ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Si Nanocrystals

AbstractThe morphology of nanocrystalline (nc)-Si/amorphous (a)-SiO2 superlattices (SLs) is studied using Raman spectroscopy in the acoustic and optical phonon ranges, transmission electron microscopy (TEM), and atomic force microscopy (AFM). It is demonstrated that high temperature annealing (up to 1100°C) and oxidation in O2/H2O ambient do not destroy the SL structure, which retains its original periodicity and nc-Si/a-SiO2 interface abruptness. It is found that oxidation at high temperatures reduces the defect density in nc-Si/a-SiO2 SLs and induces the lateral coalescence of Si nanocrystals (NCs). The size, shape, packing density, and crystallographic orientation of the Si nanocrystals are studied as a function of the oxidation time.

Structural Characterization of Low-Temperature InN Buffer Layer Grown by RF-MBE

2003 ◽  
Vol 798 ◽  
Author(s):  
T. Araki ◽  
Y. Nanishi
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Low Temperature ◽  
Buffer Layer ◽  
Molecular Beam ◽  
Cubic Phase ◽  
Local Fluctuations ◽  
Transmission Electron ◽  
Surface Migration

ABSTRACTThe microstructure of an InN buffer layer grown on (0001) sapphire at low temperature by radio-frequency molecular beam epitaxy (RF-MBE) is characterized by transmission electron microscopy. The low-temperature InN buffer layer is found to contain local inhomogeneous regions of island-like grains surrounded by misoriented InN grains and inclusions of cubic phase. The generation of such anti-phase InN nuclei near the island-like grains is expected to give rise to defects at the interface. It is considered that these anti-phase InN nuclei are formed by local fluctuations of stoichiometry due to inadequate surface migration during the growth of the InN buffer layer, indicating the important of controlling the surface stoichiometry during InN growth.

Low-temperature annealing of YBa2Cu3O7-x

1992 ◽  
Vol 50 (1) ◽  
pp. 88-89
Author(s):  
R.L. Sabatini ◽  
Yimei Zhu ◽  
Masaki Suenaga ◽  
A.R. Moodenbaugh
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Low Temperature ◽  
Oxygen Diffusion ◽  
Diffusion Rate ◽  
Oxygen Depletion ◽  
Low Temperature Annealing ◽  
Transmission Electron ◽  
Microstructural Effects ◽  
Oxygen Diffusion Rate

Low temperature annealing (<400°C) of YBa2Cu3O7x in a ozone containing oxygen atmosphere is sometimes carried out to oxygenate oxygen deficient thin films. Also, this technique can be used to fully oxygenate thinned TEM specimens when oxygen depletion in thin regions is suspected. However, the effects on the microstructure nor the extent of oxygenation of specimens has not been documented for specimens exposed to an ozone atmosphere. A particular concern is the fact that the ozone gas is so reactive and the oxygen diffusion rate at these temperatures is so slow that it may damage the specimen by an over-reaction. Thus we report here the results of an investigation on the microstructural effects of exposing a thinned YBa2Cu3O7-x specimen in an ozone atmosphere using transmission electron microscopy and energy loss spectroscopy techniques.

Characterization of submicrometer fluid Inclusions in minerals by Analytical/Transmission Electron Microscopy and electron diffraction

1990 ◽  
Vol 48 (4) ◽  
pp. 424-424
Author(s):  
George Guthrie ◽  
David Veblen
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Electron Diffraction ◽  
Light Microscopy ◽  
Fluid Inclusions ◽  
Energy Dispersive Spectrometer ◽  
Analytical Transmission Electron Microscopy ◽  
Transmission Electron

The nature of a geologic fluid can often be inferred from fluid-filled cavities (generally <100 μm in size) that are trapped during the growth of a mineral. A variety of techniques enables the fluids and daughter crystals (any solid precipitated from the trapped fluid) to be identified from cavities greater than a few micrometers. Many minerals, however, contain fluid inclusions smaller than a micrometer. Though inclusions this small are difficult or impossible to study by conventional techniques, they are ideally suited for study by analytical/ transmission electron microscopy (A/TEM) and electron diffraction. We have used this technique to study fluid inclusions and daughter crystals in diamond and feldspar.Inclusion-rich samples of diamond and feldspar were ion-thinned to electron transparency and examined with a Philips 420T electron microscope (120 keV) equipped with an EDAX beryllium-windowed energy dispersive spectrometer. Thin edges of the sample were perforated in areas that appeared in light microscopy to be populated densely with inclusions. In a few cases, the perforations were bound polygonal sides to which crystals (structurally and compositionally different from the host mineral) were attached (Figure 1).

A crystallographic analysis of the CoSi/Si(111) interface using Transmission Electron Microscopy

1990 ◽  
Vol 48 (4) ◽  
pp. 574-575
Author(s):  
A.C. Daykin ◽  
C.J. Kiely ◽  
R.C. Pond ◽  
J.L. Batstone
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Defect Structure ◽  
Room Temperature ◽  
Theoretical Method ◽  
Crystallographic Analysis ◽  
Si Substrate ◽  
Transmission Electron ◽  
Theoretical Predictions

When CoSi2 is grown onto a Si(111) surface it can form in two distinct orientations. A-type CoSi2 has the same orientation as the Si substrate and B-type is rotated by 180° degrees about the [111] surface normal.One method of producing epitaxial CoSi2 is to deposit Co at room temperature and anneal to 650°C.If greater than 10Å of Co is deposited then both A and B-type CoSi2 form via a number of intermediate silicides .The literature suggests that the co-existence of A and B-type CoSi2 is in some way linked to these intermediate silicides analogous to the NiSi2/Si(111) system. The phase which forms prior to complete CoSi2 formation is CoSi. This paper is a crystallographic analysis of the CoSi2/Si(l11) bicrystal using a theoretical method developed by Pond. Transmission electron microscopy (TEM) has been used to verify the theoretical predictions and to characterise the defect structure at the interface.

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