Growth of Epitaxial IrSi3 Layers on Si(111)

1989 ◽  
Vol 160 ◽  
Author(s):  
T. L. Lin ◽  
C. W. Nieh
Keyword(s):  
Surface Morphology ◽  
Molecular Beam ◽  
Solid Phase ◽  
Single Mode ◽  
Growth Conditions ◽  
Tem Analysis ◽  
Mbe Growth ◽  
Good Surface ◽  
Transmission Electron

AbstractEpitaxial IrSi3 films have been grown on Si (111) by molecular beam epitaxy (MBE) at temperatures ranging from 630 to 800 °C and by solid phase epitaxy (SPE) at 500 °C. Good surface morphology was observed for IrSi3 layers grown by MBE at temperatures below 680 °C, and an increasing tendency to form islands is noted in samples grown at higher temperatures. Transmission electron microscopy (TEM) analysis reveals that the IrSi3 layers grow epitaxially on Si(111) with three epitaxial modes depending on the growth conditions. For IrSi3 layers grown by MBE at 630 °C, two epitaxial modes were observed with ~ 50% area coverage for each mode. Single mode epitaxial growth was achieved at a higher MBE growth temperature, but with island formation in the IrSi3 layer. A template technique was used with MBE to improve the IrSi3 surface morphology at higher growth temperatures. Furthermore, single-crystal IrSi3 was grown on Si(111) at 500 °C by SPE, with annealing performed in-situ in a TEM chamber.

Defect morphology in thick relaxed layers of InGaAs on GaAs

1990 ◽  
Vol 48 (4) ◽  
pp. 668-669
Author(s):  
R H Dixon ◽  
P Kidd ◽  
P J Goodhew
Keyword(s):  
Electron Microscopy ◽  
Surface Morphology ◽  
Growth Conditions ◽  
X Ray Diffraction ◽  
Double Crystal ◽  
Strained Layers ◽  
Good Surface ◽  
Transmission Electron ◽  
Device Structures ◽  
Surface Morphologies

Thick relaxed InGaAs layers grown epitaxially on GaAs are potentially useful substrates for growing high indium percentage strained layers. It is important that these relaxed layers are defect free and have a good surface morphology for the subsequent growth of device structures.3μm relaxed layers of InxGa1-xAs were grown on semi - insulating GaAs substrates by Molecular Beam Epitaxy (MBE), where the indium composition ranged from x=0.1 to 1.0. The interface, bulk and surface of the layers have been examined in planar view and cross-section by Transmission Electron Microscopy (TEM). The surface morphologies have been characterised by Scanning Electron Microscopy (SEM), and the bulk lattice perfection of the layers assessed using Double Crystal X-ray Diffraction (DCXRD).The surface morphology has been found to correlate with the growth conditions, with the type of defects grown-in to the layer (e.g. stacking faults, microtwins), and with the nature and density of dislocations in the interface.

MBE Growth of GaAs on Porous Silicon

1987 ◽  
Vol 91 ◽  
Author(s):  
T. L. Lin ◽  
L. Sadwick ◽  
K. L. Wang ◽  
S. S. Rhee ◽  
Y. C Kao ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Porous Silicon ◽  
Surface Morphology ◽  
Molecular Beam ◽  
Stacking Faults ◽  
Rutherford Backscattering ◽  
Mbe Growth ◽  
Transmission Electron ◽  
Minimum Yield

ABSTRACTGaAs layers have been grown on porous silicon (PS) substrates by molecular beam epitaxyNo surface morphology deterioration was observed onGaAs-on-PS layers in spite of the roughness of PS. A 10% Rutherford backscattering spectroscopy (RBS) channeling minimum yield for GaAs-on-PS layers as compared to 16% for GaAs-on-Si layers grown under the same condition indicates a possible improvement of crystallinity when GaAs is grown on PS. Transmission electron microscopy (TEM) reveals that the dominant defects in the GaAs-on-PS layers are microtwins and stacking faults, which originate from the GaAs/PS interface. GaAs is found to penetrate into the PS layers.

Molecular Beam Epitaxical Growth of AlxGa1-xAs on non- Planar Patterned GaAs (100)

1989 ◽  
Vol 145 ◽  
Author(s):  
S. Guha ◽  
A. Madhukar ◽  
K. Kaviani ◽  
Li Chen ◽  
R. Kuchibhotla ◽  
...  
Keyword(s):  
Migration Rate ◽  
Molecular Beam ◽  
Growth Front ◽  
In Situ Growth ◽  
Cross Sectional ◽  
Mbe Growth ◽  
Quantum Well Structures ◽  
Transmission Electron ◽  
Front Profile

AbstractWe have examined some aspects of inter-facet migration during molecular beam epitaxical(MBE) growth of AlxGal-xAs on patterned GaAs (100) substrates. Scanning and cross-sectional transmission electron microscopy are employed to examine the evolution of the growth front profile. We observe significant inter facet migration from (3111/1411) facets which originate from the terrace edges to the flat terrace region. The migration length of cations on these facets is at least 0.9 μm for GaAs growth while for A10.5Ga0.5As it is less than 0.3 μm. We also observe a decreasing inter- facet migration rate with increasing growth. This interfacet migration is exploited for in situ, growth kinetics controlled, creation of laterally confined quantum well structures on the top terrace region and photoluminescence results for these structures are presented.

Strained InGaAs/GaAs Multiple Quantum Wells Grown on Planar and Pre-Patterned GaAs(100) Substrates VIA Molecular Beam Epitaxy: Applications to Light Modulators and Detectors

1991 ◽  
Vol 228 ◽  
Author(s):  
Li Chen ◽  
Kezhong Hu ◽  
K. C. Rajkumar ◽  
S. Guhae ◽  
R. Kapre ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Molecular Beam ◽  
Contrast Ratio ◽  
Growth Conditions ◽  
Optical Quality ◽  
Multiple Quantum Wells ◽  
Multiple Quantum ◽  
Mbe Growth ◽  
Light Modulators ◽  
Transmission Electron

ABSTRACTWe report the realization of high quality strained InGaAs/GaAs multiple quantum wells (MQW) grown on planar GaAs (100) substrates through optimization of molecular beam epitaxical (MBE) growth conditions and structure. Such MQWs containing ∼ 11% In have lead to the realization of an asymmetric Fabry-Perot (ASFP) reflection modulator with a room temperature contrast ratio of 66:1 and an on-state reflectivity of 30%. For In composition ≥ 0.2, the improved optical quality for very thick (gt;2μm) InGaAs/GaAs MQWs grown on pre-patterned substrates is demonstrated via transmission electron microscopy (TEM) and micro-absorption measurements.

Solid-Phase Epitaxial Regrowth of GaAs by in-situ Controlled Intermediate Phase Decomposition

1998 ◽  
Vol 4 (S2) ◽  
pp. 634-635
Author(s):  
J.K. Farrer ◽  
D.A. Caldwell ◽  
C.J. Palmstrom ◽  
C.B. Carter
Keyword(s):  
Intermediate Phase ◽  
Solid Phase ◽  
Metal Layer ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
Tem Analysis ◽  
Epitaxial Regrowth ◽  
Transmission Electron ◽  
Subsequent Decomposition

A transmission electron microscopy (TEM) analysis on the regrowth of GaAs by a two-stage reaction between a metal layer (M) and a GaAs substrate is presented. The first stage of the regrowth process is the consumption of GaAs in a low temperature reaction with the metal layer, producing an intermediate phase of (MxGaAs). A second solid-phase reaction, induced by the deposition of Ga or As, results in the decomposition of the intermediate phase and the epitaxial regrowth of a layer of GaAs. The sample growth and reactions were performed in-situ in a molecular beam epitaxy system, using Ni for the metal and As deposition for the second reaction. TEM data confirm the formation of the ternary phase, NixGaAs, and its subsequent decomposition into NiAs and GaAs by reacting with the deposited As. A layer of AlGaAs, 100 nm thick, was grown in all samples as a marker.

Dynamic studies of silicide-mediated crystallization of amorphous silicon

1992 ◽  
Vol 50 (2) ◽  
pp. 1352-1353
Author(s):  
C. Hayzelden ◽  
J. L. Batstone
Keyword(s):  
Ion Implantation ◽  
Solid Phase ◽  
Metallic Phase ◽  
Single Crystal Substrate ◽  
Free Electrons ◽  
Melt Temperature ◽  
Transmission Electron ◽  
Crystal Substrate ◽  
High Resolution Tem

Epitaxial reordering of amorphous Si(a-Si) on an underlying single-crystal substrate occurs well below the melt temperature by the process of solid phase epitaxial growth (SPEG). Growth of crystalline Si(c-Si) is known to be enhanced by the presence of small amounts of a metallic phase, presumably due to an interaction of the free electrons of the metal with the covalent Si bonds near the growing interface. Ion implantation of Ni was shown to lower the crystallization temperature of an a-Si thin film by approximately 200°C. Using in situ transmission electron microscopy (TEM), precipitates of NiSi2 formed within the a-Si film during annealing, were observed to migrate, leaving a trail of epitaxial c-Si. High resolution TEM revealed an epitaxial NiSi2/Si(l11) interface which was Type A. We discuss here the enhanced nucleation of c-Si and subsequent silicide-mediated SPEG of Ni-implanted a-Si.Thin films of a-Si, 950 Å thick, were deposited onto Si(100) wafers capped with 1000Å of a-SiO2. Ion implantation produced sharply peaked Ni concentrations of 4×l020 and 2×l021 ions cm−3, in the center of the films.

Temperature Dependent Quasi-Periodic Facetting of AlAs Grown by MBE on (100) GaAs Substrates

1993 ◽  
Vol 312 ◽  
Author(s):  
Richard Mirin ◽  
Mohan Krishnamurthy ◽  
James Ibbetson ◽  
Arthur Gossard ◽  
John English ◽  
...  
Keyword(s):  
Growth Conditions ◽  
High Energy ◽  
High Energy Electron ◽  
Temperature Dependent ◽  
Cross Sectional ◽  
Mbe Growth ◽  
Atomic Force ◽  
Gaas Substrates ◽  
Transmission Electron ◽  
Facet Formation

AbstractHigh temperature (≥ 650°C) MBE growth of AlAs and AlAs/GaAs superlattices on (100) GaAs is shown to lead to quasi-periodic facetting. We demonstrate that the facetting is only due to the AlAs layers, and growth of GaAs on top of the facets replanarizes the surface. We show that the roughness between the AlAs and GaAs layers increases with increasing number of periods in the superlattice. The roughness increases to form distinct facets, which rapidly grow at the expense of the (100) surface. Within a few periods of the initial facet formation, the (100) surface has disappeared and only the facet planes are visible in cross-sectional transmission electron micrographs. At this point, the reflection high-energy electron diffraction pattern is spotty, and the specular spot is a distinct chevron. We also show that the facetting becomes more pronounced as the substrate temperature is increased from 620°C to 710°C. Atomic force micrographs show that the valleys enclosed by the facets can be several microns long, but they may also be only several nanometers long, depending on the growth conditions.

In Situ High-Temperature Transmission Electron Microscopy Observations of the Formation of Nanocrystalline TiC from Nanocrystalline Anatase (TiO2)

1998 ◽  
Vol 4 (3) ◽  
pp. 269-277 ◽  
Author(s):  
A. Agrawal ◽  
J. Cizeron ◽  
V.L. Colvin
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Temperature ◽  
Solid Phase ◽  
Anatase Phase ◽  
High Resolution Electron Microscopy ◽  
Rutile Phase ◽  
Transmission Electron ◽  
New Phase

In this work, the high-temperature behavior of nanocrystalline TiO2 is studied using in situ transmission electron microscopy (TEM). These nanoparticles are made using wet chemical techniques that generate the anatase phase of TiO2 with average grain sizes of 6 nm. X-ray diffraction studies of nanophase TiO2 indicate the material undergoes a solid-solid phase transformation to the stable rutile phase between 600° and 900°C. This phase transition is not observed in the TEM samples, which remain anatase up to temperatures as high as 1000°C. Above 1000°C, nanoparticles become mobile on the amorphous carbon grid and by 1300°C, all anatase diffraction is lost and larger (50 nm) single crystals of a new phase are present. This new phase is identified as TiC both from high-resolution electron microscopy after heat treatment and electron diffraction collected during in situ heating experiments. Video images of the particle motion in situ show the nanoparticles diffusing and interacting with the underlying grid material as the reaction from TiO2 to TiC proceeds.

Sign in / Sign up

Export Citation Format

Share Document