Interaction between Recombination Enhanced Dislocation Glide Process Activated Basal Stacking Faults and Threading Dislocations in 4H-Silicon Carbide Epitaxial Layers

2007 ◽  
Vol 994 ◽  
Author(s):  
Yi Chen ◽  
Michael Dudley ◽  
Kendrick X Liu ◽  
Robert E Stahlbush
Keyword(s):  
Silicon Carbide ◽  
Partial Dislocation ◽  
Displacement Vector ◽  
Stacking Faults ◽  
Epitaxial Layers ◽  
Threading Dislocations ◽  
Screw Dislocations ◽  
Dislocation Glide ◽  
Shockley Partial ◽  
Partial Dislocations

AbstractElectron-hole recombination enhanced glide of Shockley partial dislocations bounding expanding stacking faults and their interactions with threading dislocations in 4H silicon carbide epitaxial layers have been studied using synchrotron white beam X-ray topography and in situ electroluminescence. The mobile silicon-core Shockley partial dislocations bounding the stacking faults are able to cut through threading edge dislocations leaving no trailing dislocation segments in their wake. However, when the Shockley partial dislocations interact with threading screw dislocations, trailing 30o partial dislocation dipoles are initially deposited in their wake due to the pinning effect of the threading screw dislocations. These dipoles spontaneously snap into their screw orientation, regardless the normally immobile carbon-core Shockley partial dislocation components in the dipoles. They subsequently cross slip and annihilate, leaving a prismatic stacking fault in (2-1-10) plane with the displacement vector 1/3[01-10].

Synchrotron X-Ray Topographic Studies of Recombination Activated Shockley Partial Dislocations in 4H-Silicon Carbide Epitaxial Layers

2008 ◽  
Vol 600-603 ◽  
pp. 357-360 ◽  
Author(s):  
Yi Chen ◽  
Xian Rong Huang ◽  
Ning Zhang ◽  
Michael Dudley ◽  
Joshua D. Caldwell ◽  
...  
Keyword(s):  
Stacking Faults ◽  
Epitaxial Layers ◽  
Threading Dislocations ◽  
X Rays ◽  
Electron Hole ◽  
X Ray ◽  
Shockley Partial ◽  
Partial Dislocations ◽  
Edge Component ◽  
Hole Recombination

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.

Differences in Emission Spectra of Dislocations in 4H-SiC Epitaxial Layers

2008 ◽  
Vol 600-603 ◽  
pp. 345-348 ◽  
Author(s):  
Kendrick X. Liu ◽  
X. Zhang ◽  
Robert E. Stahlbush ◽  
Marek Skowronski ◽  
Joshua D. Caldwell
Keyword(s):  
Spectral Characteristics ◽  
Emission Spectra ◽  
Spectral Peak ◽  
Epitaxial Layers ◽  
Threading Dislocations ◽  
Screw Dislocations ◽  
Material Defects ◽  
Partial Dislocations ◽  
Edge Dislocations ◽  
Non Destructive

Material defects such as Si-core and C-core partial dislocations (PDs) and threading screw dislocations (TSDs) and threading edge dislocations (TEDs) are being investigated for their contributions to device performances in 4H-SiC. Non-destructive electroluminescence and photoluminescence techniques can be powerful tools for examining these dislocations. In this report, these techniques were used to reveal the different spectral characteristics for the mentioned dislocations. At higher injection levels, both the Si-core and C-core PDs possessed a spectral peak at 700 nm. However, at lower injection levels, the spectral peak for the Si-core PD remained at 700 nm while the peak for the C-core moved to longer wavelengths. For the threading dislocations, TSDs possessed a peak between 800 and 850 nm while the TEDs possessed a peak at 600 nm independent of the injection levels.

Misfit Dislocations in Epitaxial Layers of SI on Gap (001) Substrates

1984 ◽  
Vol 37 ◽  
Author(s):  
M. P. A. Viegers ◽  
C. W. T. Bulle Lieuwma ◽  
P. C. Zalm ◽  
P. M. J. Maree
Keyword(s):  
Strain Field ◽  
Stacking Faults ◽  
Misfit Strain ◽  
Epitaxial Layers ◽  
Misfit Dislocations ◽  
Biaxial Strain ◽  
Burgers Vector ◽  
Shockley Partial ◽  
Partial Dislocations ◽  
Geometrical Effect

AbstractMisfit dislocations in epitaxial layers of Si grown by MBE at 570°C on GaP(001) substrates have been studied by TEM. It is found that layers as thick as 500 Å at least reside coherently on the substrate without misfit dislocations. In 1000 Å layers of Si the misfit strain is accommodated in part by 60-degree type dislocations with their Burgers vector inclined with respect to the interface, and by stacking faults intersecting the Si layer. The dislocations are dissociated into 30- and 90-degree Shockley partial dislocations. It is shown that in the case of a biaxial strain field, which is tensile in a (001)-plane, the 90-degree partial must be nucleated first. Only then can the 30-degree partial follow on the same glide plane. This geometrical effect explains the presence of dislocations as well as stacking faults in the Si layer.

Controlling Planar Defects in 3C-SiC: Ways to Wake it up as a Practical Semiconductor

2015 ◽  
Vol 821-823 ◽  
pp. 108-114 ◽  
Author(s):  
Hiroyoki Nagasawa ◽  
Ramya Gurunathan ◽  
Maki Suemitsu
Keyword(s):  
Phase Boundary ◽  
Partial Dislocation ◽  
Stacking Faults ◽  
Planar Defects ◽  
Forest Dislocation ◽  
Dislocation Glide ◽  
Partial Dislocations ◽  
Blocking Property ◽  
Trapezoidal Plate ◽  
Anti Phase Boundary

Eelectrically active defects in 3C–SiC are investigated by considering the structures and interactions of planar defects. An anti-phase boundary (APB) largely degrades the blocking property of semiconductor devices due to its semimetallic nature. Although APBs can be eliminated by orienting the specific polar face of 3C-SiC along a particular direction, stacking faults (SFs) cannot be eliminated due to Shockley-type partial dislocation glide. SFs with Shockley-type partial dislocations form a trapezoidal plate which expands the Si-terminated surface with increasing 3C-SiC thickness. Although the density of SFs can be reduced by counter termination, specific cross-junctions between a pair of counter SFs forms a forest dislocation, and this is regarded as an electrically active defect. This paper proposes an effective way to suppress the forest dislocations and APBs which nucleate during 3C-SiC growth.

Separation of the Driving Force and Radiation-Enhanced Dislocation Glide in 4H-SiC

2012 ◽  
Vol 725 ◽  
pp. 35-40 ◽  
Author(s):  
Koji Maeda ◽  
Rii Hirano ◽  
Yuki Sato ◽  
Michio Tajima
Keyword(s):  
Driving Force ◽  
Partial Dislocation ◽  
Stacking Faults ◽  
Dislocation Velocity ◽  
Electronic Excitations ◽  
Dislocation Glide ◽  
Partial Dislocations ◽  
Simultaneous Measurements ◽  
Pl Mapping ◽  
Anomalous Expansion

Anomalous expansion of stacking faults (SFs) induced in 4H-SiC under electronic excitations is driven by an electronic force and is achieved by enhanced glide of partial dislocations. An experimental attempt to separate the two physically different effects has been made by conducting photoluminescence (PL) mapping experiments which allowed simultaneous measurements of partial dislocation velocity and SF-originated PL intensity the latter of which is proposed to be related to the driving force for SF expansion through the density of free excitons planarly confined in the SF.

Structure of stacking faults in pyrite using TEM techniques

1992 ◽  
Vol 50 (1) ◽  
pp. 358-359
Author(s):  
Raja Subramanian ◽  
Kenneth S. Vecchio
Keyword(s):  
Lattice Structure ◽  
Stacking Faults ◽  
Covalent Bond ◽  
Group Symmetry ◽  
Iron Pyrite ◽  
Dislocation Glide ◽  
Partial Dislocations ◽  
Transmission Electron ◽  
Contrast Analysis ◽  
Chlorine Ions

The structure of stacking faults and partial dislocations in iron pyrite (FeS2) have been studied using transmission electron microscopy. Pyrite has the NaCl structure in which the sodium ions are replaced by iron and chlorine ions by covalently-bonded pairs of sulfur ions. These sulfur pairs are oriented along the <111> direction. This covalent bond between sulfur atoms is the strongest bond in pyrite with Pa3 space group symmetry. These sulfur pairs are believed to move as a whole during dislocation glide. The lattice structure across these stacking faults is of interest as the presence of these stacking faults has been preliminarily linked to a higher sulfur reactivity in pyrite. Conventional TEM contrast analysis and high resolution lattice imaging of the faulted area in the TEM specimen has been carried out.

Tailoring Microstructures Under Strong Non-Equilibrium Conditions: A Feasible Path Towards High JC in Melt Textured YBa2Cu3O7

2000 ◽  
Vol 659 ◽  
Author(s):  
Felip Sandiumenge ◽  
Jérôme Plain ◽  
Teresa Puig ◽  
Xavier Obradors ◽  
Jacques Rabier ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Partial Dislocation ◽  
Enhancement Factor ◽  
Stacking Faults ◽  
Equilibrium Conditions ◽  
Pinning Centers ◽  
Partial Dislocations ◽  
High Oxygen Pressure ◽  
Density Analysis ◽  
Feasible Path

ABSTRACTMelt textured YBa2Cu3O/Y2BaCuO5 were post processed by high oxygen pressure for different periods and temperatures. This process permits the control of the microstructure, in particular the growth and shape of the stacking faults and thereby the partial dislocation density. Analysis of the Jc(H,T) behavior allow to separate the contribution of Y2BaCuO5 interface from that of dislocations. It is shown that the in-plane partial dislocations act as point-like pinning centers increasing Jc up to 180% but this enhancement factor is counterbalanced by the effect of the stacking faults associated to the partial dislocations.

Threading Dislocation Density Reduction in GaN/Sapphire Heterostructures.

1999 ◽  
Vol 595 ◽  
Author(s):  
A. Kvit ◽  
A. K. Sharma ◽  
J. Narayan
Keyword(s):  
Basal Plane ◽  
Stacking Faults ◽  
High Density ◽  
Thin Layers ◽  
Interfacial Region ◽  
Threading Dislocation ◽  
Threading Dislocations ◽  
Misfit Dislocations ◽  
Plan View ◽  
Partial Dislocations

AbstractLarge lattice mismatch between GaN and α-Al2O3 (15%) leads to the possibility of high threading dislocation densities in the nitride layers grown on sapphire. This investigation focused on defect reduction in GaN epitaxial thin layer was investigated as a function of processing variables. The microstructure changes from threading dislocations normal to the basal plane to stacking faults in the basal plane. The plan-view TEM and the corresponding selected-area diffraction patterns show that the film is single crystal and is aligned with a fixed epitaxial orientation to the substrate. The epitaxial relationship was found to be (0001)GaN∥(0001)Sap and [01-10]GaN∥[-12-10]Sap. This is equivalent to a 30° rotation in the basal (0001) plane. The film is found to contain a high density of stacking faults with average spacing 15 nm terminated by partial dislocations. The density of partial dislocations was estimated from plan-view TEM image to be 7×109 cm−2. The cross-section image of GaN film shows the density of stacking faults is highest in the vicinity of the interface and decreases markedly near the top of the layer. Inverted domain boundaries, which are almost perpendicular to the film surface, are also visible. The concentration of threading dislocation is relatively low (∼;2×108 cm−2), compared to misfit dislocations. The average distance between misfit dislocations was found to be 22 Å. Contrast modulations due to the strain near misfit dislocations are seen in high-resolution cross-sectional TCM micrograph of GaN/α-Al2O3 interface. This interface is sharp and does not contain any transitional layer. The interfacial region has a high density of Shockley and Frank partial dislocations. Mechanism of accommodation of tensile, sequence and tilt disorder through partial dislocation generation is discussed. In order to achieve low concentration of threading dislocations we need to establish favorable conditions for some stacking disorder in thin layers above the film-substrate interface region.

Effect of Ta on the Structure and Dynamics of γ/α2 Interfaces in Tial

1990 ◽  
Vol 213 ◽  
Author(s):  
S. R. Singh ◽  
J. M. Howe
Keyword(s):  
Partial Dislocation ◽  
Growth Mechanisms ◽  
Tial Alloys ◽  
Shockley Partial ◽  
Structure And Dynamics ◽  
Partial Dislocations ◽  
Α2 Phase ◽  
Atomically Flat ◽  
Ledge Mechanism ◽  
Image Simulations

ABSTRACTThe structure of γ/α interfaces in binary and Ta-containing TiAl alloys were analyzed by HRTEM and image simulations. Growth of α2 was found to be due to a ledge mechanism, consisting of Shockley partial dislocations on alternate (111)γ planes. The interface is atomically flat between the ledges and addition of Ta was found to transform arrays of growth ledges in the binary alloy into islands on the plate faces in the Ta-containing alloy. These islands of α2 on the γ/α2 interfaces were 4–7nm wide and increased in size with decreasing ageing temperature. The height of the ledges and islands were always a multiple of the c-parameter (0.46nm) of the α2 phase. The islands were bounded by 90°(edge) and 30° screw) Shockley partial dislocations. The 30° partial dislocation cores were localized whereas the 90° partial dislocation cores appeared to be highly delocalized due to presence of a high density of kinks, which in one case was found to be about 0.65nm−1.These results are interpreted in terms of the growth mechanisms and morphology of the α2 phase.

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