Conversion Mechanism of Threading Screw Dislocation during SiC Solution Growth

2012 ◽  
Vol 717-720 ◽  
pp. 351-354 ◽  
Author(s):  
Toru Ujihara ◽  
Shigeta Kozawa ◽  
Kazuaki Seki ◽  
Alexander ◽  
Yuji Yamamoto ◽  
...  
Keyword(s):  
Screw Dislocation ◽  
Basal Plane ◽  
Conversion Process ◽  
Solution Growth ◽  
Powerful Method ◽  
High Quality ◽  
X Ray ◽  
Step Flow ◽  
Partial Dislocations ◽  
Step Flow Growth

Solution growth is considered to be a powerful method for high quality SiC crystals. This work reports that the conversion process from a threading screw dislocation into a few Frank partial dislocations in basal planes was investigated by synchrotron X-ray topography. This process was effectively assisted by step-flow growth on off-oriented (0001) seed crystals. The Frank partials were not extended into the crystal grown toward the [0001] direction perpendicular to the basal plane. Thus, the conclusion of this study suggests the use of off-oriented seed crystal is important to improve crystal quality.

Reduction of Threading Screw Dislocation Utilizing Defect Conversion during Solution Growth of 4H-SiC

2013 ◽  
Vol 740-742 ◽  
pp. 189-192 ◽  
Author(s):  
S. Harada ◽  
Yuji Yamamoto ◽  
Kazuaki Seki ◽  
Toru Ujihara
Keyword(s):  
Screw Dislocation ◽  
Seed Crystal ◽  
Solution Growth ◽  
Spiral Growth ◽  
High Quality ◽  
Special Shape ◽  
Screw Dislocations ◽  
Step Flow ◽  
Polytype Transformation ◽  
Step Flow Growth

Reduction of threading screw dislocation without polytype transformation from 4H-SiC was performed by the combination of step-flow growth and spiral growth. On a vicinal 4H-SiC seed crystal, threading screw dislocations are converted to Frank-type stacking faults by step-flow during solution growth. As the growth proceeds, the defects are excluded to the crystal. Thus utilizing the conversion, high quality SiC crystal growth without threading screw dislocations is expected to achieve. However, at the same time, polytype transformation is caused by the occurrence of 2D nucleation. By using the special shape of seed crystal, we successfully grew high quality 4H-SiC crystal without threading screw dislocation and polytype transformation.

Formation of Basal Plane Dislocations Introduced by Collision of Macrosteps on Growth Surface during SiC Solution Growth

2017 ◽  
Vol 897 ◽  
pp. 28-31
Author(s):  
Tsukasa Hori ◽  
Kenta Murayama ◽  
S. Harada ◽  
S. Xiao ◽  
M. Tagawa ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Surface Morphology ◽  
Basal Plane ◽  
The Other ◽  
Solution Growth ◽  
Interference Microscopy ◽  
Growth Surface ◽  
X Ray ◽  
Top Seeded Solution Growth ◽  
The Relationship

The relationship between surface morphology and spatial distribution of basal plane dislocations in 4H-SiC crystal grown by top-seeded solution growth on the C face was investigated by the differential interference microscopy as well as X-ray topography. Basal plane dislocations were generated at the boundaries of the domains with the different macrosteps advance directions. On the other hand, at the position where macrosteps advance to the same direction, BPDs were hardly observed. This results suggest that BPD density can be decreased by the suppression of the collision of macrosteps during the solution growth on the C face controlling the surface morphology.

Structure of basal plane defects formed by the conversion of threading screw dislocation during solution growth of SiC

2014 ◽  
Author(s):  
S. Harada ◽  
S.Y. Xiao ◽  
M. Tagawa ◽  
Y. Yamamoto ◽  
S. Arai ◽  
...  
Keyword(s):  
Screw Dislocation ◽  
Basal Plane ◽  
Solution Growth

Characterization of Defect Structures in Lely 6H-SiC Single Crystals Using Synchrotron White Beam X-Ray Topography

1994 ◽  
Vol 375 ◽  
Author(s):  
W. Huang ◽  
S. Wang ◽  
M. Dudley ◽  
P. Neudeck ◽  
J. A. Powell ◽  
...  
Keyword(s):  
Single Crystals ◽  
Basal Plane ◽  
Stacking Faults ◽  
Defect Structures ◽  
Dislocation Generation ◽  
X Ray ◽  
Partial Dislocations ◽  
White Beam ◽  
Generation Mechanisms

AbstractDefect structures in Lely SiC single crystals have been studied using synchrotron white beam X-ray topography. Basal plane dislocations and stacking faults probably generated during post-growth cooling are clearly revealed. For both perfect dislocations and partial dislocations bounding the stacking faults, Burgers vectors and line directions are determined from contrast extinction analysis as well as projected direction analysis on different topographic images. The fault planes and fault vectors of the stacking faults were determined using contrast extinction analysis. Possible dislocation generation mechanisms are briefly discussed.

Suppression of Polytype Transformation with Extremely Low-Dislocation-Density 4H-SiC Crystal in Two-Step Solution Method

2018 ◽  
Vol 924 ◽  
pp. 60-63 ◽  
Author(s):  
Kenta Murayama ◽  
Shunta Harada ◽  
Fumihiro Fujie ◽  
Xin Bo Liu ◽  
Ryota Murai ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Screw Dislocation ◽  
Basal Plane ◽  
Solution Method ◽  
Threading Dislocations ◽  
High Quality ◽  
Seed Crystals ◽  
Low Dislocation Density ◽  
Step Growth ◽  
Polytype Transformation

We achieved the growth of extremely-high quality SiC crystal with two-step solution method with specially-designed seed crystals. The two-step growth consists of 1st step growth on Si-face for the reduction of threading dislocations and 2nd step growth on C-face for the reduction of basal plane dislocations and thickening. In this method, we can make the dislocation density extremely low, while the polytype easily changes during growth due to the absence of spiral hillocks originating from threading screw dislocation (TSD). In this study, we prepared specially designed seed crystals for both 1st and 2nd growth steps to provide steps continuously. In the seeds, a few TSDs exist at the upper-side of the step structure. Consequently, we demonstrated the suppression of the polytype transformation during the C-face growth with extremely low-dislocation-density crystal. Accordingly, we successfully obtained extremely low-dislocation density 4H-SiC with TSD, TED and BPD density of 11, 385 and 28 cm-2.

Growth of Large AlN Single Crystals Along the [0001] Direction

2005 ◽  
Vol 892 ◽  
Author(s):  
Ziad Georges Herro ◽  
Dejin Zhuang ◽  
Raoul Schlesser ◽  
Ramon Collazo ◽  
Zlatko Sitar
Keyword(s):  
Single Crystals ◽  
Growth Parameters ◽  
High Quality ◽  
Step Flow ◽  
Large Window ◽  
Polar Surfaces ◽  
Step Flow Growth

AbstractWe have demonstrated growth of large AlN single crystals using (0001)-oriented AlN seeds. Boules with a diameter of 15 mm and length up to 12 mm were obtained from 5 mm seeds. Step flow growth was observed on both Al and N-polar surfaces. N-polar face was suitable for growth within a large window of growth parameters while the Al-polar seeds yielded high-quality crystals only at low supersaturation.

Effect of doping on crystalline quality of rubidium titanyl phosphate (RTP) crystals grown by the TSSG method

2014 ◽  
Vol 1698 ◽  
Author(s):  
Jianqiu Guo ◽  
Balaji Raghothamachar ◽  
Michael Dudley ◽  
Joan J. Carvajal ◽  
Ali Butt ◽  
...  
Keyword(s):  
Growth Process ◽  
Solution Growth ◽  
Crystalline Quality ◽  
Defect Structures ◽  
Growth Sector ◽  
High Quality ◽  
X Ray ◽  
Linear Defects ◽  
Top Seeded Solution Growth

ABSTRACTDefect structures in Rubidium Titanyl Phosphate (RTP) crystals (non-doped and doped) grown by the Top Seeded Solution Growth (TSSG) method were characterized using Synchrotron White Beam X-ray Topography. Main defects observed in non-doped crystals are growth sector boundaries while both growth sector boundaries and growth striations are observed in the Nb single doped and (Nb,Yb)-codoped crystals with relatively few linear defects such as dislocations. Results show that the overall crystalline quality is lowered as more doping elements are incorporated. Details of defect distributions are correlated with the growth process to facilitate high quality growth of doped RTP.

Solution Growth and Characterization of Icosahedral Boron Arsenide (B12As2)

2011 ◽  
Vol 1307 ◽  
Author(s):  
C.E. Whiteley ◽  
Y. Zhang ◽  
A. Mayo ◽  
J.H. Edgar ◽  
Y. Gong ◽  
...  
Keyword(s):  
Room Temperature ◽  
Solution Growth ◽  
High Quality ◽  
Burgers Vector ◽  
X Ray ◽  
Dislocation Densities ◽  
Boron Arsenide ◽  
Viable Method ◽  
Molten Nickel

ABSTRACTThe crystallographic properties of bulk icosahedral boron arsenide (B12As2) crystals grown by precipitation from molten nickel solutions were characterized. Large crystals (5-8 mm) were produced by dissolving the boron in nickel at 1150°C for 48-72 hours, reacting with arsenic vapor, and slowly cooling to room temperature. The crystals varied in color from black and opaque to clear and transparent. Raman spectroscopy, x-ray topography (XRT), and defect selective etching revealed that the B12As2 single crystals were high quality with low dislocation densities. Furthermore, XRT results suggest that the major face of the plate-like crystals was (111) type, while (100), (010) and (001) type facets were also observed optically. The predominant defect in these crystals was edge character growth dislocations with a <001> Burgers vector, and <-110> line direction. In short, XRT characterization shows that solution growth is a viable method for producing good quality B12As2 crystals.

scholarly journals Electronic‐Grade High‐Quality Perovskite Single Crystals by a Steady Self‐Supply Solution Growth for High‐Performance X‐ray Detectors

2020 ◽  
Vol 32 (33) ◽  
pp. 2001540 ◽  
Author(s):  
Wenzhen Wang ◽  
Hua Meng ◽  
Huanzhen Qi ◽  
Haitao Xu ◽  
Wenbin Du ◽  
...  
Keyword(s):  
Single Crystals ◽  
High Performance ◽  
Solution Growth ◽  
High Quality ◽  
X Ray

HVPE and MOVPE GaN Growth on Slightly Misoriented Sapphire Substrates

1999 ◽  
Vol 595 ◽  
Author(s):  
Olivier Parillaud ◽  
Volker Wagner ◽  
Hans-Jörg Bühlmann ◽  
François Lelarge ◽  
Marc Ilegems
Keyword(s):  
Substrate Surface ◽  
Growth Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Step Flow ◽  
Sapphire Substrates ◽  
Atomic Force ◽  
Step Flow Growth ◽  
Gan Buffer Layer

AbstractWe present preliminary results on gallium nitride growth by HVPE on C-plane sapphire with 2, 4 and 6 degrees misorientation towards M and A directions. A nucleation GaN buffer layer is deposited prior the growth by MOVPE. Surface morphology and growth rates are compared with those obtained on exact C-plane oriented sapphire, for various growth conditions. As expected, the steps already present on the substrate surface help to initiate a directed step-flow growth mode. The large hillocks, which are typical for HVPE GaN layers on (0001) sapphire planes, are replaced by more or less parallel macro-steps. The width and height of these steps, due to step bunching effect, depend directly on the angle of misorientation and on the growth conditions, and are clearly visible by optical or scanning electron microscopy. Atomic force microscopy and X-ray diffraction measurements have been carried out to quantify the surface roughness and crystal quality.

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