Structural Studies of Nucleation and the Initial Stages of Growth of Epitaxial Gaas on Si(100) Substrates

1986 ◽  
Vol 82 ◽  
Author(s):  
R. Hull ◽  
A. Fischer-Colbrie ◽  
S.J. Rosner ◽  
S.M. Koch ◽  
J.S. Harris
Keyword(s):  
Molecular Beam ◽  
Gaas Layer ◽  
Island Size ◽  
Epitaxial Gaas ◽  
Stages Of Growth ◽  
Transmission Electron ◽  
Initial Nucleation ◽  
Gaas Films ◽  
Secondary Defect ◽  
Island Coalescence

ABSTRACTNucleation and growth of GaAs fIlms deposited by Molecular Beam Epitaxy upon Si(l00) substrates are studied by transmission electron microscopy. The initial nucleation of GaAs consists of approximately hemispherical islands associated with steps upon the substratesurface and coherently strained to the substrate lattice. As the island size increases, crystalline defects relax the strain between epilayer and substrate. Island coalescence is a secondary defect generation mechanism. Subsequent growth of the epitaxial GaAs layer reveals a progressive deterioration of the GaAs/Si interface planarity and the growth and eventual dissolution of amorphous or misoriented crystalline regions at the GaAs/Si interface.

Very Thin 2D GaAs Films on Si During the Early Stages of Growth by MBE

1989 ◽  
Vol 159 ◽  
Author(s):  
D.B. Fenner ◽  
D.K. Biegelsen ◽  
B.S. Krusor ◽  
F.A. Ponce ◽  
J.C. Tramontana
Keyword(s):  
Electron Spectroscopy ◽  
Molecular Beam ◽  
Flux Ratio ◽  
Cross Sectional ◽  
Stages Of Growth ◽  
Transmission Electron ◽  
Gaas Films ◽  
Lattice Images ◽  
Graded Thickness

ABSTRACTGaAs samples deposited on Si by molecular beam epitaxy (MBE) with a graded thickness of 0–3 nm initially show the presence of a metastable two dimensional (2D) layer containing Ga and As. In the thicker regions of the wedge samples, islands (3D topography) form in the presence of the 2D sea, i.e., Stranski – Krastanov growth. Compositional profiles of these wedges were made with in situ Auger electron spectroscopy (AES) which has allowed the identification of at least four regimes of growth. Lattice images from cross – sectional transmission electron microscopy (XTEM) are consistent with the AES profiles. Substrate temperature during deposition of the films has a strong effect on film topography, as does the beam – flux ratio on film stoichiometry.

Growth and Characterizations of Gaas on Inp with Different Buffer Structures by Molecular Beam Epitaxy

1989 ◽  
Vol 148 ◽  
Author(s):  
Xiaoming Liu ◽  
Henry P. Lee ◽  
Shyh Wang ◽  
Thomas George ◽  
Eicke R. Weber ◽  
...  
Keyword(s):  
Low Temperature ◽  
Buffer Layer ◽  
Gaas Layer ◽  
Optical Quality ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Layer Structures ◽  
Gaas Films ◽  
Initial Deposition ◽  
Strained Layer Superlattices

ABSTRACTWe report the growth and characterizations of 31μm thick GaAs films grown on (100) InP substrates by MBE employing different buffer layer structures during the initial deposition. The buffer layer structures under study are: 1) GaAs layer grown at low temperature; 2) GaAs layer grown at low temperature plus two sets of In0.08Ga0.92As/GaAs strained layer superlattices (SLS) and 3) a transitional compositionally graded InxGal-xAs layer between the InP substrate and the GaAs film. After the buffer layer deposition, the growth was continued by conventionalMBE to a total thickness of 3μm for all samples. From the 77K photoluminescence (PL) measurement, it was found that the sample with SLS layers has the highest PL intensity and the narrowest PL linewidth. Cross-sectional transmission electron microscopy (TEM) studies showed that the SLS is effective in reducing the propagation of threading dislocations and explains the observed superior optical quality from the PL measurement.

Investigation of crystal properties of TmP/GaAs and GaAs/TmP/GaAs heterostructures grown by molecular beam epitaxy

2001 ◽  
Vol 16 (11) ◽  
pp. 3266-3273 ◽  
Author(s):  
C. H. Lin ◽  
R. J. Hwu ◽  
L. P. Sadwick
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Surface Segregation ◽  
Secondary Ion Mass Spectrometry ◽  
Gaas Layer ◽  
Force Microscopy ◽  
Transmission Electron ◽  
Crystal Properties ◽  
Device Applications ◽  
Composition Profiles

Single-crystal thulium phosphide (TmP) was grown heteroepitaxially on (001) GaAs substrates by molecular beam epitaxy with the orientation relationship [100]TmP//[100]GaAs and {001}TmP//{001}GaAs. The crystal properties and the defects in TmP/GaAs, GaAs/TmP/GaAs heterostructure were characterized through x-ray diffraction, atomic force microscopy, and transmission electron microscopy. TmP was found to have a huge difference in thermal expansion coefficient compared GaAs, which produced high tensile residual stress and may result in the formation of defects. The major defects in the top GaAs layer are stacking faults or microtwins, and they directly correlated with the islandlike surface morphology of the GaAs overlayer. The composition profiles of the TmP/GaAs heterostructure were measured by secondary ion mass spectrometry. The reason for surface segregation of Tm and Ga atoms is discussed and is primarily due to their higher diffusion coefficient near the surface as compared to that in the TmP epilayer bulk. The thermally stable characters of the TmP/GaAs heterostructures allow them to be promising candidates in various device applications.

Defects in Mbe-Grown GaAs/ScxEr1–xAs/GaAs Layers

1990 ◽  
Vol 198 ◽  
Author(s):  
Jane G. Zhu ◽  
Chris J. Palmstrdøm ◽  
C. Barry Carter
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Molecular Beam Epitaxy ◽  
Growth Stage ◽  
Molecular Beam ◽  
Gaas Layer ◽  
Stacking Fault ◽  
Initial Growth ◽  
Gaas Substrates ◽  
Transmission Electron

ABSTRACTThe microstructure and the structure of defects in GaAs/ScxEr1–xAs/GaAs (x=0 and 0.3) heterostructures grown on (100) GaAs substrates by molecular beam epitaxy have been characterized using transmission electron microscopy. The top GaAs layer forms islands on ScxEr1–xAs at the initial growth stage, and the area covered by GaAs varies with the growth temperature. In addition to regions of epitactic (100) GaAs, regions of {122}- and (111)-oriented GaAs are observed on (100)-oriented ScxEr1–xAs. A high density of stacking-fault pyramids is found in epilayers of GaAs grown on a thin epilayer of ErAs, where the ErAs layers are only one or two monolayers thick. The apex of each stacking-fault pyramid is located at the ScxEr1–xAs/GaAs interface.

Strain-Field Induced Crosshatch Formation During Molecular Beam Epitaxy of InGaAs/GaAs Films

1993 ◽  
Vol 312 ◽  
Author(s):  
X. C. Zhou ◽  
J. Jiang ◽  
A. Y. Du ◽  
J. W. Zhao ◽  
S. M. Mu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Direct Evidence ◽  
Surface Strain ◽  
Misfit Dislocations ◽  
Strain Fields ◽  
Transmission Electron ◽  
Gaas Films ◽  
Reflection Electron Microscopy

AbstractUsing reflection electron microscopy (REM), transmission electron microscopy (TEM), and Nomarski optical microscopy we obtained direct evidence that local surface strain-fields, originated from misfit dislocations, are responsible for the formation of morphological crosshatches during molecular beam epitaxy of lattice mismatched InGaAs/GaAs layers. A mechanism is proposed to correlate the formation of the crosshatched patterns with the variation of the growth rate across the epitaxial surface under the perturbation of network shaped strain-fields in the surface.

Influence of Antimony Doping on Nanoscale Arsenic Clusters and Dislocation Loops in Low-Temperature Grown Gallium Arsenide Films

2000 ◽  
Vol 652 ◽  
Author(s):  
V.V. Chaldyshev ◽  
N.A. Bert ◽  
A.E. Romanov ◽  
A.A. Suvorova ◽  
A.L. Kolesnikova ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Low Temperature ◽  
Molecular Beam ◽  
Dislocation Loops ◽  
Gaas Matrix ◽  
Transmission Electron ◽  
Antimony Doping ◽  
Gaas Films ◽  
Sb Doping ◽  
Ripening Rate

ABSTRACTTransmission electron microscopy was employed to study the microstructure of GaAs films grown by molecular-beam epitaxy at low temperature and delta-doped with Sb. Thus obtained material contained 0.5 at.% of excess arsenic that precipitates upon post-growth anneals. The Sb doping was found to strongly affect the microstructure of arsenic clusters and their ripening rate upon annealing. Segregation of Sb impurities in the As clusters was revealed. In contrast to the well known pure As clusters, the As-Sb clusters induced strong local deformations in the surrounding GaAs matrix. Relaxation of these deformations resulted in formation of dislocation loops, which was studied both experimentally and theoretically.

scholarly journals Epitaxial GaAs Films Deposited by Molecular Beam Method

1973 ◽  
Vol 93 (10) ◽  
pp. 434-440
Author(s):  
M. NAGANUMA ◽  
K. TAKAHASHI
Keyword(s):  
Molecular Beam ◽  
Epitaxial Gaas ◽  
Beam Method ◽  
Gaas Films
Sign in / Sign up

Export Citation Format

Share Document