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 ◽  
...  

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.

1990 ◽  
Vol 198 ◽  
Author(s):  
Jane G. Zhu ◽  
C. Barry Carter ◽  
Chris J. Palmstrom

ABSTRACTThe formation and structures of misfit dislocations are significant factors in understanding heteroepitaxy of lattice-mismatched materials. In this study, GaAs/Si, CoGa/GaAs and ErAs/GaAs heterojunctions in materials grown by molecular-beam epitaxy have been characterized using transmission electron microscopy. Different types of misfit dislocations have been generated at these interfaces. The different dislocation configurations are discussed, along with interactions between 60° and 90° dislocations in GaAs/Si heterojunctions; the 60° dislocations might be associated with surface steps or edges of islands. The growth of antiphase boundary structures in the CoGa and ErAs grown on GaAs are proposed.


1984 ◽  
Vol 41 ◽  
Author(s):  
S. H. Chen ◽  
P. Enquist ◽  
C. B. Carter

AbstractHeavily Sn-doped GaAs films have been grown by molecular-beam epitaxy and found to contain single-crystal Sn particles situated in the near-surface region of the epilayer GaAs. The morphology and chemical composition of the particles have been examined by using cross-section transmission electron microscopy combined with energy-dispersive x-ray spectroscopy. Different growth conditions were used to study the Sn-particle formation and high-resolution transmission electron microscopy was used to investigate microstructures. The observations are discussed in terms of several models previously proposed for these phenomena.


2016 ◽  
Vol 30 (20) ◽  
pp. 1650269 ◽  
Author(s):  
Thi Giang Le ◽  
Minh Tuan Dau

High-resolution transmission electron microscopy (HR-TEM) has been used to investigate the structural properties of GeMn/Ge nanocolumns multilayer samples grown on Ge(001) substrates by means of molecular beam epitaxy (MBE) system. Four bilayers with the spacer thickness in the range between 6 nm and 15 nm and 10 periods of bilayers of Ge[Formula: see text]Mn[Formula: see text]/Ge nanocolumn are presented. A simplified 2D model based on the theory of elastic constant interactions has been used to provide reasonable explanations to the vertical self-organization of GeMn nanocolumns in multilayers.


1987 ◽  
Vol 102 ◽  
Author(s):  
Richard J. Dalby ◽  
John Petruzzello

ABSTRACTOptical and transmission electron microscopy have been used to study cracks appearing in ZnSe/ZnSxSe1−x (x ∼ 0.38) superlattices grown by Molecular Beam Epitaxy. It Is shown that when a fracture occurs it is confined, in most cases, to the superlattice and propagates along <011> cleavage directions in these <001> oriented epilayers. Cracks were not observed in all superlattices and their onset is discussed in relation to sulfur concentration, overall superlattice height, individual superlattice layer thicknesses, and stress, tensile or compressive, due to lattice mismatch and thermal expansion differences between buffer layer and superlattice. It was found that by adjusting the controllable parameters, cracks in the superlattices could be eliminated. Orientation and density of these features have been related to asynnmetric cracking associated with the zincblende structure of these II-VI materials. Experimental results are shown to be in agreement with theoretical predictions of critical heights for the onset of cracking.


2019 ◽  
Vol 963 ◽  
pp. 127-130
Author(s):  
Jörg Pezoldt ◽  
Charbel Zgheib ◽  
Thomas Stauden ◽  
Gernot Ecke ◽  
Thomas Kups ◽  
...  

Ternary (Si1-xCy)Gex+y solid solutions were grown on Si-face 4H-SiC applying atomic layer molecular beam epitaxy at low temperatures. The grown layers consist of twinned 3C-SiC revealed by cross section electron microscopy. The germanium was incorporated on silicon lattice sites as revealed by atomic location by channeling enhanced microanalysis transmission electron microscopy studies. The Ge concentration of the grown 3C-(Si1-xCy)Gex+y heteroepitaxial layers decreases with increasing growth temperatures, but exceeds the solid solubility limit.


2001 ◽  
Vol 43 (1) ◽  
pp. 151-156 ◽  
Author(s):  
V. V. Mamutin ◽  
N. A. Cherkashin ◽  
V. A. Vekshin ◽  
V. N. Zhmerik ◽  
S. V. Ivanov

Crystals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 899
Author(s):  
Hong-Yi Yang ◽  
Ikai Lo ◽  
Cheng-Da Tsai ◽  
Ying-Chieh Wang ◽  
Huei-Jyun Shih ◽  
...  

Lattice relaxation on wurtzite GaN microdisks grown by plasma-assisted molecular beam epitaxy was systematically studied. The lattice constants of GaN microdisks were evaluated from high-resolution transmission electron microscopy, and the anisotropic strain was then analyzed by observing the microscopic atomic layers. We found that the vertical lattice strain along the c-axis followed a linear relationship, while the lateral lattice strain along the a-axis exhibited a quadratic deviation. The lattice mismatch is about 0.94% at the interface between the GaN microdisks and the γ-LiAlO2 substrate, which induces the anisotropic strain during epi-growth.


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