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.

Correlation between Thermal Stress and Formation of Interfacial Dislocations during 4H-SiC Epitaxy and Thermal Annealing

2011 ◽  
Vol 679-680 ◽  
pp. 306-309 ◽  
Author(s):  
Xuan Zhang ◽  
Masahiro Nagano ◽  
Hidekazu Tsuchida
Keyword(s):  
Thermal Stress ◽  
Temperature Gradient ◽  
Thermal Annealing ◽  
Thermal Strain ◽  
Misfit Strain ◽  
Misfit Dislocations ◽  
Radial Temperature Gradient ◽  
Radial Temperature ◽  
Interfacial Dislocations

Interfacial dislocations are frequently observed to form during 4H-SiC epitaxy and thermal annealing. This report attempts to establish the correlation between the distribution of interfacial dislocations and the thermal stress induced by a radial temperature gradient. In addition, it is argued that they are misfit dislocations formed by the interaction between thermal strain and misfit strain.

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.

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.

In situ TEM measurements of the electrical properties of interface dislocations

1992 ◽  
Vol 50 (2) ◽  
pp. 1338-1339
Author(s):  
F. M. Ross ◽  
R. Hull ◽  
D. Bahnck ◽  
J. C. Bean ◽  
L. J. Peticolas ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Electronic Device ◽  
In Situ Tem ◽  
Device Performance ◽  
Misfit Dislocations ◽  
Electrical Characteristics ◽  
Strained Layer ◽  
Transmission Electron ◽  
Interfacial Dislocations

We describe an investigation of the electrical properties of interfacial dislocations in strained layer heterostructures. We have been measuring both the structural and electrical characteristics of strained layer p-n junction diodes simultaneously in a transmission electron microscope, enabling us to correlate changes in the electrical characteristics of a device with the formation of dislocations.The presence of dislocations within an electronic device is known to degrade the device performance. This degradation is of increasing significance in the design and processing of novel strained layer devices which may require layer thicknesses above the critical thickness (hc), where it is energetically favourable for the layers to relax by the formation of misfit dislocations at the strained interfaces. In order to quantify how device performance is affected when relaxation occurs we have therefore been investigating the electrical properties of dislocations at the p-n junction in Si/GeSi diodes.

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.

Relationship between misfit-dislocation formation and initial threading-dislocation density in GaInN/GaN heterostructures

2015 ◽  
Vol 54 (11) ◽  
pp. 115501 ◽  
Author(s):  
Motoaki Iwaya ◽  
Taiji Yamamoto ◽  
Daisuke Iida ◽  
Yasunari Kondo ◽  
Mihoko Sowa ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Misfit Dislocation ◽  
Threading Dislocation ◽  
Threading Dislocation Density ◽  
Dislocation Formation

Stars and stripes. Nanoscale misfit dislocation patterns on surfaces

2002 ◽  
Vol 74 (9) ◽  
pp. 1663-1671 ◽  
Author(s):  
Raghani Pushpa ◽  
Shobhana Narasimhan
Keyword(s):  
Surface Structure ◽  
Misfit Dislocation ◽  
Domain Walls ◽  
Chemical Potential ◽  
Model System ◽  
Misfit Dislocations ◽  
Face Centered Cubic ◽  
Hexagonal Close Packed ◽  
Structure Changes ◽  
Face Centered

Close-packed metal surfaces and heteroepitaxial systems frequently display a structure consisting of regularly spaced misfit dislocations, with a network of domain walls separating face-centered cubic (fcc) and hexagonal close-packed (hcp) domains. These structures can serve as templates for growing regularly spaced arrays of nanoislands. We present a theoretical investigation of the factors controlling the size and shape of the domains, using Pt(111) as a model system. Upon varying the chemical potential, the surface structure changes from being unreconstructed to the honeycomb, wavy triangles, "bright stars", or Moiré patterns observed experimentally on Pt(111) and other systems. For the particular case of Pt(111), isotropically contracted star-like patterns are favored over uniaxially contracted stripes.

The effect of implantation temperature on the mechanism of misfit dislocation formation

1978 ◽  
Vol 45 (2) ◽  
pp. 377-385 ◽  
Author(s):  
V. V. Kalinin ◽  
N. N. Gerasimenko ◽  
S. I. Stenin
Keyword(s):  
Misfit Dislocation ◽  
Implantation Temperature ◽  
Dislocation Formation

Impact of a strong temperature gradient on grain growth in films

2021 ◽  
Author(s):  
Dana Zöllner
Keyword(s):  
Temperature Gradient ◽  
Grain Growth ◽  
Annealing Temperature ◽  
Three Dimensional ◽  
Drag Effect ◽  
Temperature Changes ◽  
Grain Boundary Mobility ◽  
Microstructural Coarsening ◽  
Temporal And Spatial ◽  
Model Algorithm

Abstract The migration of grain boundaries and, therewith, the phenomenon of grain growth depend strongly on the annealing temperature. Generally, higher temperatures are associated with higher mobilities of the boundaries and therewith faster microstructural coarsening. In the present study, the influence of a strong temperature gradient on grain growth in thin films is investigated. To that aim, a modified three-dimensional Potts model algorithm is employed, where the annealing temperature changes with the thickness of the sample taking grain boundary mobility and energy into account. The resulting drag effect has serious consequences for the temporal and spatial evolution of the grain microstructure.

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