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Title: Observations of the Influence of Threading Dislocations on the Recombination Enhanced Partial Dislocation Glide in 4H-Silicon Carbide Epitaxial Layers

Abstract

Electron-hole recombination enhanced glide of Shockley partial dislocations bounding expanding stacking faults and their interactions with threading dislocations have been studied in 4H- silicon carbide epitaxial layers. The mobile silicon-core Shockley partial dislocations bounding the stacking faults are observed to cut through threading edge dislocations, leaving no trailing dislocation segments in their wake. When the Shockley partial dislocations interact with threading screw dislocations, 30 degree partial dislocation dipoles are initially deposited in their wake. These partial dislocation dipoles quickly and spontaneously snap into screw orientation whereupon they cross slip and annihilate, leaving a prismatic stacking fault on the (2{ovr 11}0) plane.

Authors:
; ; ;
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL) National Synchrotron Light Source
Sponsoring Org.:
Doe - Office Of Science
OSTI Identifier:
930668
Report Number(s):
BNL-81165-2008-JA
Journal ID: ISSN 0003-6951; APPLAB; TRN: US200901%%172
DOE Contract Number:
DE-AC02-98CH10886
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 90
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CARBIDES; DIPOLES; DISLOCATIONS; EDGE DISLOCATIONS; ORIENTATION; RECOMBINATION; SCREW DISLOCATIONS; SILICON CARBIDES; SLIP; STACKING FAULTS; national synchrotron light source

Citation Formats

Chen,Y., Dudley, M., Liu, K., and Stahlbush, R. Observations of the Influence of Threading Dislocations on the Recombination Enhanced Partial Dislocation Glide in 4H-Silicon Carbide Epitaxial Layers. United States: N. p., 2007. Web. doi:10.1063/1.2734499.
Chen,Y., Dudley, M., Liu, K., & Stahlbush, R. Observations of the Influence of Threading Dislocations on the Recombination Enhanced Partial Dislocation Glide in 4H-Silicon Carbide Epitaxial Layers. United States. doi:10.1063/1.2734499.
Chen,Y., Dudley, M., Liu, K., and Stahlbush, R. Mon . "Observations of the Influence of Threading Dislocations on the Recombination Enhanced Partial Dislocation Glide in 4H-Silicon Carbide Epitaxial Layers". United States. doi:10.1063/1.2734499.
@article{osti_930668,
title = {Observations of the Influence of Threading Dislocations on the Recombination Enhanced Partial Dislocation Glide in 4H-Silicon Carbide Epitaxial Layers},
author = {Chen,Y. and Dudley, M. and Liu, K. and Stahlbush, R.},
abstractNote = {Electron-hole recombination enhanced glide of Shockley partial dislocations bounding expanding stacking faults and their interactions with threading dislocations have been studied in 4H- silicon carbide epitaxial layers. The mobile silicon-core Shockley partial dislocations bounding the stacking faults are observed to cut through threading edge dislocations, leaving no trailing dislocation segments in their wake. When the Shockley partial dislocations interact with threading screw dislocations, 30 degree partial dislocation dipoles are initially deposited in their wake. These partial dislocation dipoles quickly and spontaneously snap into screw orientation whereupon they cross slip and annihilate, leaving a prismatic stacking fault on the (2{ovr 11}0) plane.},
doi = {10.1063/1.2734499},
journal = {Applied Physics Letters},
number = ,
volume = 90,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
  • Grazing-incidence synchrotron white beam x-ray topography images of closed-core threading screw dislocations in 4H silicon carbide appear as roughly elliptically shaped white features, with an asymmetric perimeter of dark contrast which is greatly enhanced on one side or other of the g vector. Ray-tracing simulations indicate that the relative position of the enhanced dark contrast feature reveals the sense of the closed-core screw dislocation. Dislocation senses so obtained were validated using back-reflection images recorded with small Bragg angle. Therefore, the sense of the closed-core threading screw dislocations can be unambiguously revealed using either grazing-incidence or 'small Bragg angle' back-reflection synchrotronmore » white beam x-ray topography.« less
  • Electron-hole recombination-activated partial dislocations in 4H silicon carbide homoepitaxial layers and their behavior have been studied using synchrotron X-ray topography and electroluminescence. Stacking faults whose expansion was activated by electron-hole recombination enhanced dislocation glide were observed to be bounded by partial dislocations, which appear as white stripes or narrow dark lines in back-reflection X-ray topographs recorded using the basal plane reflections. Such contrast variations are attributable to the defocusing/focusing of the diffracted X-rays due to the edge component of the partial dislocations, which creates a convex/concave distortion of the basal planes. Simulation results based on the ray-tracing principle confirm ourmore » argument. Observations also indicate that, when an advancing partial dislocation interacts with a threading screw dislocation, a partial dislocation dipole is dragged behind in its wake. This partial dislocation dipole is able to advance regardless of the immobility of the C-core segment. A kink pushing mechanism is introduced to interpret the advancement of this partial dislocation dipole.« less
  • Electron-hole recombination-activated partial dislocations in 4H silicon carbide homoepitaxial layers and their behavior have been studied using synchrotron X-ray topography and electroluminescence. Stacking faults whose expansion was activated by electron-hole recombination enhanced dislocation glide were observed to be bounded by partial dislocations, which appear as white stripes or narrow dark lines in back-reflection X-ray topographs recorded using the basal plane reflections. Such contrast variations are attributable to the defocusing/focusing of the diffracted X-rays due to the edge component of the partial dislocations, which creates a convex/concave distortion of the basal planes. Simulation results based on the ray-tracing principle confirm ourmore » argument. Observations also indicate that, when an advancing partial dislocation interacts with a threading screw dislocation, a partial dislocation dipole is dragged behind in its wake. This partial dislocation dipole is able to advance regardless of the immobility of the C-core segment. A kink pushing mechanism is introduced to interpret the advancement of this partial dislocation dipole.« less
  • Electron-hole recombination activated Shockley partial dislocations bounding expanding stacking faults and their interactions with threading dislocations have been studied in 4H-SiC epitaxial layers using synchrotron x-ray topography. The bounding partials appear as white stripes or narrow dark lines in back-reflection X-ray topographs recorded using the basal plane reflections. Such contrast variations are attributable to the defocusing/focusing of the diffracted X-rays due to the edge component of the partial dislocations, which creates a convex/concave distortion of the basal planes. Simulation results based on the ray-tracing principle confirm our argument. The sign of the partial dislocations can be subsequently determined.
  • A model is presented for the formation mechanism of dislocation half-loop arrays formed during the homoepitaxial growth of 4H-SiC. The reorientation during glide of originally screw oriented threading segments of basal plane dislocation (BPD) renders them susceptible to conversion into sessile threading edge dislocations (TEDs), which subsequently pin the motion of the BPD. Continued glide during further growth enables parts of the mobile BPD to escape through the surface leaving arrays of half loops comprising two TEDs and a short BPD segment with significant edge component. The faulting behavior of the arrays under UV excitation is consistent with this model.