Growth of (GaAs)1−x (Si2)x Metastable Alloys using Migration-Enhanced Epitaxy

1991 ◽  
Vol 222 ◽  
Author(s):  
T. Sudersena Rao ◽  
Y. Horikoshi
Keyword(s):  
Buffer Layers ◽  
Double Crystal ◽  
Cross Sectional ◽  
Strained Layer ◽  
Si Substrates ◽  
Migration Enhanced Epitaxy ◽  
Strained Layer Superlattice ◽  
Metastable Alloys ◽  
Si Content ◽  
Strained Layer Superlattices

ABSTRACTEpitaxial (GaAs)1−x (Si2)x metastable alloys have been grown on GaAs (100) substrates using Migration-Enhanced Epitaxy in the composition range of 0<x<0.25. The lattice constant a0 of the alloys was found to decrease with increasing Si content from 0.56543nm at x=0 to 0.5601nm at x=0.25. Double-crystal x-ray diffraction rocking curve measurements and cross-sectional transmission electron microscopy studies made on a 10 period (GaAs)1−x(Si2)x/GaAs strained layer superlattice indicated sharp and abrupt interfaces. High crystalline quality GaAs has been grown on Si substrates using (GaAs)0.80(Si2)0.20/GaAs strained layer superlattices as buffer layers.

Defect Reduction in GaAs Epilayers on Si Substrates Using Strained Layer Superlattices

1987 ◽  
Vol 91 ◽  
Author(s):  
N. El-Masry ◽  
N. Hamaguchi ◽  
J.C.L. Tarn ◽  
N. Karam ◽  
T.P. Humphreys ◽  
...  
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Buffer Layers ◽  
Threading Dislocations ◽  
Defect Reduction ◽  
Strained Layer ◽  
Si Substrates ◽  
Density Of Dislocations ◽  
Strained Layer Superlattice ◽  
Strained Layer Superlattices

ABSTRACTInxGa11-xAs-GaAsl-yPy strained layer superlattice buffer layers have been used to reduce threading dislocations in GaAs grown on Si substrates. However, for an initially high density of dislocations, the strained layer superlattice is not an effective filtering system. Consequently, the emergence of dislocations from the SLS propagate upwards into the GaAs epilayer. However, by employing thermal annealing or rapid thermal annealing, the number of dislocation impinging on the SLS can be significantly reduced. Indeed, this treatment greatly enhances the efficiency and usefulness of the SLS in reducing the number of threading dislocations.

Structural Defects in InSb Quantum Wells Grown on GaAs (001) Substrates via Al0.09In0.91Sb/GaSb-AlSb Strained Layer Superlattice/AlSb/GaSb Buffer Layers

2005 ◽  
Vol 891 ◽  
Author(s):  
Tetsuya D. Mishima ◽  
Madhavie Edirisooriya ◽  
Michael B. Santos
Keyword(s):  
Quantum Wells ◽  
Buffer Layer ◽  
Defect Density ◽  
Buffer Layers ◽  
Structural Defects ◽  
Tem Analysis ◽  
Cross Sectional ◽  
Plan View ◽  
Strained Layer ◽  
Strained Layer Superlattice

ABSTRACTStructural defects in InSb quantum well (QW) samples have been investigated by transmission electron microscopy (TEM). Using molecular beam epitaxy, an InSb QW with remotely-doped Al0.09In0.91Sb barriers was grown on a GaAs (001) substrate with buffer layers consisting of, in order from the substrate: 1 μm of GaSb, 1 μm of AlSb, 50 nm of GaSb-AlSb strained layer superlattice (SLS), and 3 μm of Al0.09In0.91Sb. Cross-sectional TEM analysis indicates that high densities of threading dislocations (TDs) are created at the two highly lattice-mismatched interfaces, the Al0.09In0.91Sb/GaSb-AlSb SLS and the GaSb/GaAs interfaces. Pairs of stereo images taken from plan-view TEM (PV-TEM) specimens show that TDs propagate through the InSb QW layer. The densities of TDs and micro-twin (MT) defects measured by PV-TEM are 9×108/cm2 and 4×103/cm, respectively. These values are worse than those in an InSb QW layer grown with a different buffer layer by a factor of ∼4. The different buffer layer contains an InSb interlayer that effectively filters out both TDs and MTs. Adopting an interlayer structure and reducing the GaSb and AlSb layer thickness may make it possible to fabricate a lower-defect-density yet thinner InSb QW sample with the type of buffer layer examined in this study.

Evaluation of Anti-Phase-Boundaries in GaAs/Si Heterostructures by Transmission Electron Microscopy

1989 ◽  
Vol 148 ◽  
Author(s):  
O. Ueda ◽  
T. Soga ◽  
T. Jimbo ◽  
M. Umeno
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Three Dimensional ◽  
Buffer Layers ◽  
Phase Boundaries ◽  
Cross Sectional ◽  
Si Substrates ◽  
Transmission Electron ◽  
Strained Layer Superlattices ◽  
And Behavior

ABSTRACTThe nature and behavior of anti-phase-boundaries in GaAs/Si heterostructures using GaP, GaP/GaAsP and GaAsP/GaAs strained layer superlattices as intermediate buffer layers, have been investigated by transmission electron microscopy. It has been found that anti-phasedomains are very complicated three dimensional polygons consisting of several sub-boundaries in different orientations. Self-annihilation of anti-phase-domains during crystal growth of GaAs on (001)just or (001)2°off Si substrates is directly observed for the first time through planview and cross-sectional observations. Based on these findings, a mechanism of annihilation of these domains is proposed.

On the Existence of Multiple Equilibrium States in Strained-Layer Superlattices

1987 ◽  
Vol 103 ◽  
Author(s):  
William C. Johnson
Keyword(s):  
Free Energy ◽  
Equilibrium State ◽  
Stable Equilibrium ◽  
Multiple Equilibrium ◽  
Equilibrium Thermodynamic ◽  
Relative Thickness ◽  
Two Phase ◽  
Strained Layer ◽  
Strained Layer Superlattice ◽  
Strained Layer Superlattices

ABSTRACTUsing recent results from the thermodynamics of stressed solids, two-phase coexistence in a simple binary strained-layer superlattice is examined. We show that for a given temperature and overall composition of the superlattice, there can exist more than one linearly stable, equilibrium thermodynamic state. That is, there may exist several combinations of relative thickness of the phases and corresponding phase compositions that minimize the free energy of the system. The equilibrium state observed experimentally can, therefore, be influenced by the processing path.

scholarly journals The Growth of InAsSb/InGaAs Strained-Layer Superlattices by Metal-Organic Chemical Vapor Deposition

1993 ◽  
Vol 325 ◽  
Author(s):  
R. M. Biefeld ◽  
K. C. Baucom ◽  
S. R. Kurtz ◽  
D. M. Follstaedt
Keyword(s):  
Chemical Vapor Deposition ◽  
Thermodynamic Model ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Strained Layer ◽  
Strained Layer Superlattice ◽  
Metal Organic ◽  
Strained Layer Superlattices ◽  
Organic Chemical Vapor Deposition

AbstractWe have grown InAsl-xSbx/Inl-yGayAs strained-layer superlattice (SLS) semiconductors lattice matched to InAs using a variety of conditions by metal-organic chemical vapor deposition. The V/III ratio was varied from 2.5 to 10 at a temperature of 475 °C, at pressures of 200 to 660 torr and growth rates of 3 - 5 A/s and layer thicknesses ranging from 55 to 152 Å. The composition of the InAsSb ternary can be predicted from the input gas molar flow rates using a thermodynamic model. At lower temperatures, the thermodynamic model must be modified to take account of the incomplete decomposition of arsine and trimethylantimony. Diodes have been prepared using Zn as the p-type dopant and undoped SLS as the n-type material. The diode was found to emit at 3.56 μm. These layers have been characterized by optical microscopy, SIMS, x-ray diffraction, and transmission electron diffraction. The optical properties of these SLS's were determined by infrared photoluminescence and absorption measurements.

scholarly journals The Structure of GaAs/Si(211) Heteroepitaxial Layers

1987 ◽  
Vol 91 ◽  
Author(s):  
Zuzanna Liliental-Weber ◽  
E.R. Weber ◽  
J. Washburn ◽  
T.Y. Liu ◽  
H. Kroemer
Keyword(s):  
Buffer Layer ◽  
Surface Preparation ◽  
Gaas Layer ◽  
Misfit Dislocations ◽  
Strained Layer ◽  
Si Substrates ◽  
Density Of Dislocations ◽  
Gaas Buffer Layer ◽  
Graded Layers ◽  
Strained Layer Superlattices

ABSTRACTGallium arsenide films grown on (211)Si by molecular-beam epitaxy have been investigated using transmission electron microscopy. The main defects observed in the alloy were of misfit dislocations, stacking faults, and microtwin lamellas. Silicon surface preparation was found to play an important role on the density of defects formed at the Si/GaAs interface.Two different types of strained-layer superlattices, InGaAs/InGaP and InGaAs/GaAs, were applied either directly to the Si substrate, to a graded layer (GaP-InGaP), or to a GaAs buffer layer to stop the defect propagation into the GaAs films. Applying InGaAs/GaAs instead of InGaAs/InGaP was found to be more effective in blocking defect propagation. In all cases of strained-layer superlattices investigated, dislocation propagation was stopped primarily at the top interface between the superlattice package and GaAs. Graded layers and unstrained AlGaAs/GaAs superlattices did not significantly block dislocations propagating from the interface with Si. Growing of a 50 nm GaAs buffer layer at 505°C followed by 10 strained-layer superlattices of InGaAs/GaAs (5 nm each) resulted in the lowest dislocation density in the GaAs layer (∼;5×l07/cm2) among the structures investigated. This value is comparable to the recently reported density of dislocations in the GaAs layers grown on (100)Si substrates [8]. Applying three sets of the same strained layersdecreased the density of dislocations an additional ∼2/3 times.

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