Dependence of Threading Dislocation Density on Substrate Misorientation in In0.15Ga0.85As Grown on GaAs(100)

1989 ◽  
Vol 145 ◽  
Author(s):  
P.N. Uppal ◽  
J.S. Ahearn ◽  
R. Herring
Keyword(s):  
Dislocation Density ◽  
Strain Relaxation ◽  
Dislocation Network ◽  
Uniform Density ◽  
Threading Dislocation ◽  
Dislocation Mobility ◽  
Transmission Electron ◽  
Dislocation Arrays ◽  
Threading Dislocation Density ◽  
Strained Layer Superlattices

AbstractThe density and arrangement of dislocations in In0.15Ga0.85As grown on GaAs(100)) were determined by transmission electron microscopy as a function of misorientation toward (111)A, (111)B, and (110). Strained layer superlattices were used in all cases to reduce dislocation density. Layers grown on exact GaAs(100) exhibited a non-uniform threading dislocation dis- tribution whereby some areas had a high density (∼ 109cm-2or higher) of dislocation tangles and other areas that we in between had a more uniform density (∼ 2 x 107cm-2). The misorientated layers exhibited a uniform threading dislocation distribution with densities of ∼ 5 x 106 cm-2 for (100) misoriented towards (111)A, ∼ 1 x 107cm-2towards (111)B, and ∼ 3 x 107cm-2 towards (110). The misfit dislocation network (dislocations located at the GaAs-InO0.15Ga0.85 As interface) formed orthogonal dislocation arrays in the case of exact (100) substrates and slightly non-ortho- gonal arrays in the case of misoriented substrates. These results are explained with the help of a general glide model of strain relaxation in which the exact (100) orientation has eight equally stressed glide systems which presumably activate during strain relaxation. With misoriented substrates the stress symmetry is broken and fewer glide systems experience the maximum stress, thus reducing the number of active dislocation systems. A small asymmetry in interfacial dis- location density was observed in all the cases where the linear dislocation density along the two (011) and (011) orthogonal directions differed by about 20%. This is explained by the preferred activation of (x-dislocations (high dislocation mobility) over 13-dislocations (low dislocation mobility).

Defect-Engineered Graded GexSi1-x Buffers on Si (001) with Extreme Low Threading Dislocation Density

1995 ◽  
Vol 378 ◽  
Author(s):  
G. Kissinger ◽  
T. Morgenstern ◽  
G. Morgenstern ◽  
H. B. Erzgräber ◽  
H. Richter
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Atomic Force Microscopy ◽  
Dislocation Density ◽  
Threading Dislocation ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Dislocation Densities ◽  
Threading Dislocation Density

AbstractStepwise equilibrated graded GexSii-x (x≤0.2) buffers with threading dislocation densities between 102 and 103 cm−2 on the whole area of 4 inch silicon wafers were grown and studied by transmission electron microscopy, defect etching, atomic force microscopy and photoluminescence spectroscopy.

Cantilever Epitaxy of GaN on Sapphire: Further Reductions in Dislocation Density

2002 ◽  
Vol 743 ◽  
Author(s):  
D. M. Follstaedt ◽  
P. P. Provencio ◽  
D. D. Koleske ◽  
C. C. Mitchell ◽  
A. A. Allerman ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Dislocation Density ◽  
Threading Dislocation ◽  
Threading Dislocations ◽  
Processing Conditions ◽  
Optimum Growth ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Threading Dislocation Density

ABSTRACTThe density of vertical threading dislocations at the surface of GaN grown on sapphire by cantilever epitaxy has been reduced with two new approaches. First, narrow mesas (<1 μm wide) were used and {11–22} facets formed over them early in growth to redirect dislocations from vertical to horizontal. Cross-sectional transmission electron microscopy was used to demonstrate this redirection and to identify optimum growth and processing conditions. Second, a GaN nuc-leation layer with delayed 3D → 2D growth transition and inherently lower threading dislocation density was adapted to cantilever epitaxy. Several techniques show that a dislocation density of only 2–3×107/cm2 was achieved by combining these two approaches. We also suggest other developments of cantilever epitaxy for reducing dislocations in heteroepitaxial systems.

Strain relaxation and threading dislocation density in helium-implanted and annealed Si1−xGex/Si(100) heterostructures

2004 ◽  
Vol 95 (10) ◽  
pp. 5347-5351 ◽  
Author(s):  
J. Cai ◽  
P. M. Mooney ◽  
S. H. Christiansen ◽  
H. Chen ◽  
J. O. Chu ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Strain Relaxation ◽  
Threading Dislocation ◽  
Threading Dislocation Density

Reduction of Threading Dislocation Density in InN Film Grown with in situ Surface Modification by Radio-frequency Plasma-excited Molecular Beam Epitaxy

MRS Advances ◽  
2018 ◽  
Vol 3 (18) ◽  
pp. 931-936
Author(s):  
F. B. Abas ◽  
R. Fujita ◽  
S. Mouri ◽  
T. Araki ◽  
Y. Nanishi
Keyword(s):  
Surface Modification ◽  
Electrical Properties ◽  
Dislocation Density ◽  
Hall Effect Measurement ◽  
Threading Dislocation ◽  
X Ray ◽  
Transmission Electron ◽  
Threading Dislocation Density ◽  
Order Of Magnitude

ABSTRACTThe objective of this study was to investigate the relationship between the thickness of N radical irradiated InN template with crystallographic quality and electrical properties of InN film grown with the previously proposed method, in situ surface modification by radical beam irradiation. In this study, three InN samples were grown with this method on different thickness of irradiated templates. The crystallographic quality of InN films was analyzed by X-ray diffraction and the electrical properties were studied by Hall effect measurement. InN grown on 100 nm thick irradiated template shows lower full-width at half-maximum of X-ray rocking curves and lower carrier concentration compared to InN grown on 200 nm and 450 nm thick irradiated templates. Transmission electron microscopy revealed that threading dislocation density in the InN film decreased by an order of magnitude to ∼4.6×109cm-2. These results suggest that this method is possible for reduction of threading dislocation density in InN and the thickness of irradiated template should be minimized for higher crystallographic quality and electrical properties of the entire InN film.

scholarly journals On the Study of Dislocation Density in MBE GaSb-Based Structures

Crystals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1074
Author(s):  
Agata Jasik ◽  
Dariusz Smoczyński ◽  
Iwona Sankowska ◽  
Andrzej Wawro ◽  
Jacek Ratajczak ◽  
...  
Keyword(s):  
High Resolution ◽  
Dislocation Density ◽  
Measurement Techniques ◽  
Threading Dislocation ◽  
X Ray Diffraction ◽  
Gaas Sample ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Threading Dislocation Density

The results of the study on threading dislocation density (TDD) in homo- and heteroepitaxial GaSb-based structures (metamorphic layers, material grown by applying interfacial misfit array (IMF) and complex structures) deposited using molecular beam epitaxy are presented. Three measurement techniques were considered: high-resolution x-ray diffraction (HRXRD), etch pit density (EPD), and counting tapers on images obtained using atomic force microscopy (AFM). Additionally, high-resolution transmission electron microscopy (HRTEM) was used for selected samples. The density of dislocations determined using these methods varied, e.g., for IMF-GaSb/GaAs sample, were 6.5 × 108 cm−2, 2.2 × 106 cm−2, and 4.1 × 107 cm−2 obtained using the HRXRD, EPD, and AFM techniques, respectively. Thus, the value of TDD should be provided together with information about the measurement method. Nevertheless, the absolute value of TDD is not as essential as the credibility of the technique used for optimizing material growth. By testing material groups with known parameters, we established which techniques can be used for examining the dislocation density in GaSb-based structures.

scholarly journals Single-Crystalline Si1−xGex (x = 0.5~1) Thin Films on Si (001) with Low Threading Dislocation Density Prepared by Low Temperature Molecular Beam Epitaxy

2019 ◽  
Vol 9 (9) ◽  
pp. 1772
Author(s):  
Gu ◽  
Zhao ◽  
Ye ◽  
Deng ◽  
Lu
Keyword(s):  
Thin Films ◽  
Molecular Beam Epitaxy ◽  
Low Temperature ◽  
Dislocation Density ◽  
Molecular Beam ◽  
Strain Relaxation ◽  
Relaxation Mechanism ◽  
Threading Dislocation ◽  
Threading Dislocation Density ◽  
Typical Strain

Single-crystalline Si1−xGex thin films on Si (100) with low threading dislocation density (TDD) are highly desired for semiconductor industrials. It is challenging to suppress the TDD since there is a large mismatch (4.2%) between Ge and Si—it typically needs 106–107/cm2 TDD for strain relaxation, which could, however, cause device leakage under high voltage. Here, we grew Si1−xGex (x = 0.5–1) films on Si (001) by low temperature molecular beam epitaxy (LT-MBE) at 200 °C, which is much lower than the typical temperature of 450–600 °C. Encouragingly, the Si1−xGex thin films grown by LT-MBE have shown a dramatically reduced TDD down to the 103–104/cm2 level. Using transmission electron microscopy (TEM) with atomic resolution, we discovered a non-typical strain relaxation mechanism for epitaxial films grown by LT-MBE. There are multiple-layered structures being introduced along out-of-plane-direction during film growth, effectively relaxing the large strain through local shearing and subsequently leading to an order of magnitude lower TDD. We presented a model for the non-typical strain relaxation mechanism for Si1−xGex films grown on Si (001) by LT-MBE.

In Situ Study of Isothermal Strain Relaxation in Si-Ge Heteroepitaxial Films Using Substrate Curvature Measurements

1991 ◽  
Vol 239 ◽  
Author(s):  
Véronique T. Gillard ◽  
David B. Noble ◽  
William D. Nix
Keyword(s):  
Dislocation Density ◽  
Laser Scanning ◽  
Isothermal Annealing ◽  
Strain Relaxation ◽  
Threading Dislocation ◽  
Relaxation Measurements ◽  
Threading Dislocation Density ◽  
Device Applications ◽  
Curvature Measurements

ABSTRACTUnderstanding die kinetics and mechanisms of strain relaxation in Si-Ge heteroepitaxial films is pertinent to several device applications. In this paper we present a method for determining the evolution of the mobile dislocation density with time during the course of strain relaxation taking place in an isothermal annealing experiment.Wafer curvature measurements using a laser scanning technique are used to determine the elastic strain after growth in films of variable thickness and to follow the strain relaxation during isothermal annealing experiments. By coupling the strain relaxation measurements with previous TEM measurements of dislocation velocities in this system, the mobile threading dislocation density and its evolution with time are determined.

Reduction of threading dislocation density in SiGe layers on Si (001) using a two-step strain–relaxation procedure

2001 ◽  
Vol 79 (21) ◽  
pp. 3398-3400 ◽  
Author(s):  
Akira Sakai ◽  
Ken Sugimoto ◽  
Takeo Yamamoto ◽  
Masahisa Okada ◽  
Hiroya Ikeda ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Strain Relaxation ◽  
Threading Dislocation ◽  
Threading Dislocation Density ◽  
Relaxation Procedure ◽  
Step Strain

Dislocation Density Reduction in GaAs Epilayers on Si Using Strained Layer Superlattices

1989 ◽  
Vol 160 ◽  
Author(s):  
S. Sharan ◽  
J. Narayan ◽  
J. C. C. Fan
Keyword(s):  
Dislocation Density ◽  
Defect Density ◽  
Full Potential ◽  
Threading Dislocation ◽  
Threading Dislocations ◽  
Strained Layer ◽  
Density Reduction ◽  
Threading Dislocation Density ◽  
Superlattice Structures ◽  
Strained Layer Superlattices

AbstractDefects such as dislocations and interfaces play a crucial role in the performance of heterostracture devices. The full potential of GaAs on Si heterostructures can only be realized by controlling the defect density. The reduction of threading dislocations by the use of strained layer superlattices has been studied in these heterostructures. Several superlattice structures have been used to reduce the density of threading dislocations in the GaAs epilayer. The use of strained layer superlattices in conjunction with rapid thermal annealing was most effective in reducing threading dislocation density. Transmission electron microscopy has been used to study the dislocation density reduction and the interaction of threading dislocations with the strained layers. A model has been developed based on energy considerations to determine the critical thickness required for the bending of threading dislocations.

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