Interfacial Stability and Misfit Dislocation Formation in InAs/Gaas(110) Heteroepitaxy

1997 ◽  
Vol 505 ◽  
Author(s):  
Luis A. Zepeda-Ruiz ◽  
Dimitrios Maroudas ◽  
W. Henry Weinberg
Keyword(s):  
Misfit Dislocation ◽  
Film Surface ◽  
Atomic Scale ◽  
Recent Experimental Data ◽  
Misfit Dislocations ◽  
Interfacial Stability ◽  
Coherent Interface ◽  
Gaas Buffer Layer ◽  
Critical Film Thickness ◽  
Dislocation Formation

ABSTRACTA comprehensive atomic-scale study is presented of the mechanical behavior of the InAs epitaxial film, the interfacial stability with respect to misfit dislocation formation, and the film surface morphology in InAs/GaAs(110) heteroepitaxy. If a GaAs buffer layer of ten-monolayer thickness is used in the epitaxial growth, a transition is predicted from a coherent to a semi- coherent interface consisting of a regular array of edge interfacial misfit dislocations at a critical film thickness of six monolayers. A second transition to a semicoherent interface consisting of a completely developed network of perpendicularly intersecting misfit dislocations is predicted at thicknesses greater than 150 monolayers. Our simulation results are in excellent agreement with recent experimental data.

Multiscale Analysis of Interfacial Stability and Misfit Dislocation Formation in Layer-By-Layer Semiconductor Heteroepitaxy

1998 ◽  
Vol 538 ◽  
Author(s):  
L. A. Zepeda-Ruiz ◽  
D. Maroudas ◽  
W. H. Weinberg
Keyword(s):  
Misfit Dislocation ◽  
Morphological Characteristics ◽  
Film Surface ◽  
Dislocation Network ◽  
Recent Experimental Data ◽  
Layer By Layer ◽  
Interfacial Stability ◽  
Strain Fields ◽  
Dislocation Formation ◽  
Continuum Elasticity

AbstractA theoretical analysis based on continuum elasticity theory and atomistic simulations is presented of the interfacial stability with respect to misfit dislocation formation, the strain fields, and the film surface morphology during layer-by-layer semiconductor heteroepitaxy. The energetics of the transition from a coherent to a semicoherent interface consisting of a misfit dislocation network, the structure of this semicoherent interface, the resulting strain fields and the morphological characteristics of the epitaxial film surfaces are calculated for InAs/GaAs(111)A. Continuum elasticity is found to describe the atomistic simulation results very well. Our theoretical results are discussed in the context of recent experimental data.

Interfacial Stability and Surface Morphology in Layer-By-Layer Semiconductor Heteroepitaxy Luis

1998 ◽  
Vol 528 ◽  
Author(s):  
A. Zepeda-Ruiz ◽  
Dimitrios Maroudas ◽  
W. Henry Weinberg
Keyword(s):  
Surface Morphology ◽  
Misfit Dislocation ◽  
Finite Thickness ◽  
Surface Profile ◽  
Film Surface ◽  
Layer Growth ◽  
Recent Experimental Data ◽  
Layer By Layer ◽  
Interfacial Stability ◽  
Strained Films

AbstractA theoretical analysis based on continuum elasticity theory and atomistic simulations is presented of the interfacial stability with respect to misfit dislocation formation and of the film surface morphology during layer-by-layer growth semiconductor heteroepitaxy. The strain in the coherently strained films, the energetics of a transition from a coherent to a semicoherent interface consisting of misfit dislocation arrays or networks, and the morphological details of the film surface profile are calculated for InAs/GaAs(110) and InAs/GaAs(111)A. The analysis is presented for the general case of heteroepitaxy on a finite-thickness compliant substrate. The results are discussed in the context of recent experimental data.

Interfacial stability and misfit dislocation formation in InAs/GaAs(110) heteroepitaxy

1998 ◽  
Vol 411 (3) ◽  
pp. L865-L871 ◽  
Author(s):  
Dimitrios Maroudas ◽  
Luis A. Zepeda-Ruiz ◽  
W.Henry Weinberg
Keyword(s):  
Misfit Dislocation ◽  
Interfacial Stability ◽  
Dislocation Formation

Relaxation of Misfit Dislocations at Nodes

2014 ◽  
Vol 783-786 ◽  
pp. 515-520 ◽  
Author(s):  
Shuai Shao ◽  
Jian Wang ◽  
Amit Misra ◽  
Richard G. Hoagland
Keyword(s):  
Misfit Dislocation ◽  
Mechanical Stability ◽  
Experimental Studies ◽  
Atomistic Simulations ◽  
Misfit Dislocations ◽  
Formation Processes ◽  
Coherent Interface ◽  
Core Energy ◽  
Structures And Properties ◽  
Coherent Interfaces

Experimental studies proved that structures and properties of misfit dislocations and their intersections (nodes) in semi-coherent interfaces strongly affect thermal and mechanical stability of interface. Employing atomistic simulations, we reveal that misfit dislocation lines can exhibit a spiral pattern (SP) or remain straight in association with dislocation character at nodes. By analyzing nodes formation processes in terms of kinetics and energetics, we found that the variation is ascribed to the competition between core energy of misfit dislocation and interface stacking fault energy with respect to coherent interface.

Tm Analysis of Interfaces Beiween Nb and Al2O3 Precipitates

1986 ◽  
Vol 82 ◽  
Author(s):  
W. Mader
Keyword(s):  
Misfit Dislocation ◽  
Diffraction Gratings ◽  
Al Alloy ◽  
Misfit Dislocations ◽  
Dislocation Theory ◽  
Coherent Interface ◽  
Periodic Arrays ◽  
Partially Coherent ◽  
Dislocation Arrangement

ABSTRACTA Nb—Al alloy has been internally oxidized to produce A12O3precipitates. The interface between plate—like AI2O3 precipitates and the Nb matrix has been investigated by diffraction, CTEM, and HREM techniques. Periodic arrays of misfit dislocations were observed which acted as diffraction gratings for the electrons. The location of misfit dislocation cores could be determined from HREM images within an accuracy of a few lattice spacings. It can be concluded that the misfit dislocations lead to a good matching of atomic rows across the interface. The dislocation arrangement at this partially coherent interface is in accordance with theoretical expectations from dislocation theory.

Critical Conditions of Misfit Dislocation Formation in 4H-SiC Epilayers

2012 ◽  
Vol 717-720 ◽  
pp. 313-318 ◽  
Author(s):  
Xuan Zhang ◽  
Tetsuya Miyazawa ◽  
Hidekazu Tsuchida
Keyword(s):  
Temperature Gradient ◽  
Misfit Dislocation ◽  
Annealing Temperature ◽  
Critical Value ◽  
Critical Conditions ◽  
Formation Mechanisms ◽  
Misfit Dislocations ◽  
Interfacial Dislocations ◽  
Annealing Experiments ◽  
Dislocation Formation

Thermal annealing experiments were performed to determine the critical conditions of misfit dislocation formation in 4H-SiC epilayers in a temperature range of 1400-1800 °C. Misfit dislocations were observed to form at a given annealing temperature if the temperature gradient across the epi-wafer exceeded a critical value. It was also found that two types of interfacial dislocations could form under different stress conditions. Their formation mechanisms are discussed.

Mechanisms and Kinetics of Misfit Dislocation Formation in Heteroepitaxial Thin Films

1990 ◽  
Vol 188 ◽  
Author(s):  
W. D. Nix ◽  
D. B. Noble ◽  
J. F. Turlo
Keyword(s):  
Misfit Dislocation ◽  
Strain Relaxation ◽  
Dislocation Motion ◽  
Dislocation Nucleation ◽  
Dislocation Segment ◽  
Threading Dislocation ◽  
Misfit Dislocations ◽  
Film Substrate ◽  
Kinetics Of ◽  
Dislocation Formation

ABSTRACTThe mechanisms and kinetics of forming misfit dislocations in heteroepitaxial films are studied. The critical thickness for misfit dislocation formation can be found by considering the incremental extension of a misfit dislocation by the movement of a “threading” dislocation segment that extends from the film/substrate interface to the free surface of the film. This same mechanism allows one to examine the kinetics of dislocation motion and to illuminate the importance of dislocation nucleation and multiplication in strain relaxation. The effects of unstrained epitaxial capping layers on these processes are also considered. The major effects of such capping layers are to inhibit dislocation nucleation and multiplication. The effect of the capping layer on the velocity of the “threading” dislocation is shown to be small by comparison.A new substrate curvature technique for measuring the strain and studying the kinetics of strain relaxation in heteroepitaxial films is also briefly described.

scholarly journals Atomic-Scale Insights on Large-Misfit Heterointerfaces in LSMO/MgO/c-Al2O3

Crystals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1493
Author(s):  
Soumya Mandal ◽  
Ashish Kumar Gupta ◽  
Braxton Hays Beavers ◽  
Vidit Singh ◽  
Jagdish Narayan ◽  
...  
Keyword(s):  
Misfit Dislocation ◽  
Strain Relaxation ◽  
Image Data ◽  
Atomic Displacement ◽  
Atomic Scale ◽  
Misfit Dislocations ◽  
Interfacial Chemistry ◽  
Lsmo Film ◽  
Scanning Transmission ◽  
Lattice Planes

Understanding the interfaces in heterostructures at an atomic scale is crucial in enabling the possibility to manipulate underlying functional properties in correlated materials. This work presents a detailed study on the atomic structures of heterogeneous interfaces in La0.7Sr0.3MnO3 (LSMO) film grown epitaxially on c-Al2O3 (0001) with a buffer layer of MgO. Using aberration-corrected scanning transmission electron microscopy, we detected nucleation of periodic misfit dislocations at the interfaces of the large misfit systems of LSMO/MgO and MgO/c-Al2O3 following the domain matching epitaxy paradigm. It was experimentally observed that the dislocations terminate with 4/5 lattice planes at the LSMO/MgO interface and with 12/13 lattice planes at the MgO/c-Al2O3 interface. This is consistent with theoretical predictions. Using the atomic-resolution image data analysis approach to generate atomic bond length maps, we investigated the atomic displacement in the LSMO/MgO and MgO/c-Al2O3 systems. Minimal presence of residual strain was shown at the respective interface due to strain relaxation following misfit dislocation formation. Further, based on electron energy-loss spectroscopy analysis, we confirmed an interfacial interdiffusion within two monolayers at both LSMO/MgO and MgO/c-Al2O3 interfaces. In essence, misfit dislocation configurations of the LSMO/MgO/c-Al2O3 system have been thoroughly investigated to understand atomic-scale insights on atomic structure and interfacial chemistry in these large misfit systems.

Quasiperiodic interfaces: HREM observations of grain and phase boundaries

1990 ◽  
Vol 48 (4) ◽  
pp. 332-333
Author(s):  
K. L. Merkle
Keyword(s):  
Atomic Structure ◽  
Direct Determination ◽  
Lattice Parameter ◽  
Atomic Scale ◽  
Misfit Dislocations ◽  
Oxide Systems ◽  
Atomic Structures ◽  
Periodic Arrays ◽  
Parameter Ratio ◽  
Metal Metal

The atomic structures of internal interfaces have recently received considerable attention, not only because of their importance in determining many materials properties, but also because the atomic structure of many interfaces has become accessible to direct atomic-scale observation by modem HREM instruments. In this communication, several interface structures are examined by HREM in terms of their structural periodicities along the interface.It is well known that heterophase boundaries are generally formed by two low-index planes. Often, as is the case in many fcc metal/metal and metal/metal-oxide systems, low energy boundaries form in the cube-on-cube orientation on (111). Since the lattice parameter ratio between the two materials generally is not a rational number, such boundaries are incommensurate. Therefore, even though periodic arrays of misfit dislocations have been observed by TEM techniques for numerous heterophase systems, such interfaces are quasiperiodic on an atomic scale. Interfaces with misfit dislocations are semicoherent, where atomically well-matched regions alternate with regions of misfit. When the misfit is large, misfit localization is often difficult to detect, and direct determination of the atomic structure of the interface from HREM alone, may not be possible.

Misfit Dislocations in the Ilmenite (FeTiO3)-Hematite (Fe2O3) System

1980 ◽  
Vol 38 ◽  
pp. 212-213 ◽  
Author(s):  
K.P.D. Lagerlöf ◽  
A.H. Heuer ◽  
T.E. Mitchell
Keyword(s):  
Misfit Dislocation ◽  
Lattice Parameters ◽  
Dislocation Network ◽  
Misfit Dislocations ◽  
Space Group ◽  
Two Phases ◽  
Hematite Fe2o3

It has been reported by Lally et. al. [1] that precipitates of hematite (Fe2O3, space group R3c) in a matrix of ilmenite (FeTiO3, space group R3) are lens shaped and flattened along the [0001]-direction. The coherency across the interface is lost by the introduction of a misfit dislocation network, which minimizes the strain due to the deviation in lattice parameters between the two phases [2]. The purpose of this paper is to present a new analysis of this network.

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