Structural Analysis of Dislocations in Highly Nitrogen-Doped 4H-SiC Substrates

2010 ◽  
Vol 645-648 ◽  
pp. 311-314 ◽  
Author(s):  
Masakazu Katsuno ◽  
Noboru Ohtani ◽  
Masashi Nakabayashi ◽  
Tatsuo Fujimoto ◽  
Hirokatsu Yashiro ◽  
...  
Keyword(s):  
Structural Analysis ◽  
Basal Plane ◽  
Selective Etching ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
High Concentration ◽  
X Ray ◽  
Nitrogen Doped ◽  
Low Resistivity

Dislocations in highly nitrogen-doped (N > 1×1019 cm-3) low-resistivity ( < 10 mcm) 4H-SiC substrates were investigated by photoluminescence imaging, synchrotron X-ray topography, and defect selective etching using molten KOH. The behavior of dislocations is discussed particularly in terms of their glide motion in the presence of a high concentration of nitrogen. The results indicate that nitrogen impurities up to mid 1019 cm-3 concentration do not show any discernible influence on the glide behavior of basal plane dislocations (BPDs) in 4H-SiC crystals grown by physical vapor transport (PVT) method.

Low Defect Density Bulk AlN Substrates for High Performance Electronics and Optoelectronics

2012 ◽  
Vol 717-720 ◽  
pp. 1287-1290 ◽  
Author(s):  
Balaji Raghothamachar ◽  
Rafael Dalmau ◽  
Baxter Moody ◽  
H. Spalding Craft ◽  
Raoul Schlesser ◽  
...  
Keyword(s):  
Single Crystal ◽  
Basal Plane ◽  
High Performance ◽  
Defect Density ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Threading Dislocations ◽  
Crystalline Perfection ◽  
X Ray

Using the physical vapor transport (PVT) method, single crystal boules of AlN have been grown and wafers sliced from them have been characterized by synchrotron white beam X-ray topography (SWBXT) in conjunction with optical microscopy. X-ray topographs reveal that the wafers contain dislocations that are inhomogeneously distributed with densities varying from as low as 0 cm-2 to as high as 104 cm-2. Two types of dislocations have been identified: basal plane dislocations and threading dislocations, both having Burgers vectors of type 1/3<112-0> indicating that their origin is likely due to post-growth deformation. In some cases, the dislocations are arranged in low angle grain boundaries. However, large areas of the wafers are nearly dislocation-free and section X-ray topographs of these regions reveal the high crystalline perfection.

High Quality AlN Single Crystal Substrates for AlGaN-Based Devices

2018 ◽  
Vol 924 ◽  
pp. 923-926 ◽  
Author(s):  
Rafael Dalmau ◽  
H. Spalding Craft ◽  
Jeffrey Britt ◽  
Elizabeth Paisley ◽  
Baxter Moody ◽  
...  
Keyword(s):  
Aluminum Nitride ◽  
Single Crystal ◽  
Basal Plane ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
High Magnification ◽  
High Quality ◽  
X Ray ◽  
Surface Finishes ◽  
Edge Dislocations

Aluminum nitride (AlN) single crystal boules were grown by physical vapor transport (PVT). Diameter expansion during boule growth, without the introduction of low angle grain boundaries (LAGB) around the boule periphery, was confirmed by crossed polarizer imaging, synchrotron white beam x-ray topography (SWBXT), and synchrotron monochromatic beam x-ray topography (SMBXT). The densities of basal plane dislocations (BPD) and threading edge dislocations (TED) averaged from high-magnification topographs of five regions of a high-quality substrate were 0 cm-2 and 992 cm-2, respectively. Substrates fabricated from AlN boules possessed excellent surface finishes suitable for epitaxy.

X-Ray Topographic Studies of Defects in PVT 6H-SiC Substrates and Epitaxial 6H-SiC Thin Films

1994 ◽  
Vol 339 ◽  
Author(s):  
S. Wang ◽  
M. Dudley ◽  
C. H. Carter ◽  
H. S. Kong
Keyword(s):  
Thin Films ◽  
Basal Plane ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Epitaxial Thin Films ◽  
Defect Structures ◽  
Screw Dislocations ◽  
X Ray ◽  
Back Reflection ◽  
White Beam

ABSTRACTSynchrotron white beam X-ray topography has been used to characterize defect structures in (0001) 6H-SiC substrates grown by the sublimation physical vapor transport (PVT) technique as well as in 6H-SiC epitaxial thin films grown on these substrates. Defects revealed in 6H-SiC substrates include super screw dislocations and basal plane dislocations. It has been found that back-reflection topographs are particularly suitable for imaging such super screw dislocations as well as basal plane dislocations whenever transmission topography is not applicable. Epitaxial 6H-SiC thin films grown on such (0001) substrates (tilted a few degrees towards the a-axis) were also examined by using surface sensitive grazing Bragg-Laue topography. It has been shown that super screw dislocations were replicated in the epitaxial thin films but no basal plane dislocations were revealed in the thin films. Results from various topographic techniques are discussed.

Investigation of heavily nitrogen-doped n+ 4H–SiC crystals grown by physical vapor transport

2009 ◽  
Vol 311 (6) ◽  
pp. 1475-1481 ◽  
Author(s):  
Noboru Ohtani ◽  
Masakazu Katsuno ◽  
Masashi Nakabayashi ◽  
Tatsuo Fujimoto ◽  
Hiroshi Tsuge ◽  
...  
Keyword(s):  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Nitrogen Doped

Structural Characterization of the Growth Front of 4H-SiC Boules Grown Using the Physical Vapor Transport Growth Method

2018 ◽  
Vol 924 ◽  
pp. 15-18
Author(s):  
Masashi Sonoda ◽  
Kentaro Shioura ◽  
Takahiro Nakano ◽  
Noboru Ohtani ◽  
Masakazu Katsuno ◽  
...  
Keyword(s):  
High Resolution ◽  
Surface Morphology ◽  
Defect Structure ◽  
Growth Front ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
X Ray Diffraction ◽  
X Ray ◽  
Growth Method

The defect structure at the growth front of 4H-SiC boules grown using the physical vapor transport (PVT) method has been investigated using high resolution x-ray diffraction and x-ray topography. The crystal parameters such as the c-lattice constant exhibited characteristic variations across the growth front, which appeared to be caused by variation in surface morphology of the as-grown surface of the boules rather than the defect structure underneath the surface. X-ray topography also revealed that basal plane dislocations are hardly nucleated at the growth front during PVT growth of 4H-SiC crystals.

Bulk Growth of Low Resistivity n-Type 4H-SiC Using Co-Doping

2017 ◽  
Vol 897 ◽  
pp. 3-6 ◽  
Author(s):  
Hiromasa Suo ◽  
Kazuma Eto ◽  
Tomohisa Kato ◽  
Kazutoshi Kojima ◽  
Hiroshi Osawa ◽  
...  
Keyword(s):  
Vapor Deposition ◽  
Chemical Vapor ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
X Ray ◽  
Co Doping ◽  
Bulk Growth ◽  
Dislocation Densities ◽  
Growth Method ◽  
Co Doped

The growth of n-type 4H-SiC crystal was performed by physical vapor transport (PVT) growth method by using nitrogen and aluminum (N-Al) co-doping. Resistivity of N-Al co-doped 4H-SiC was as low as 5.8 mΩcm. The dislocation densities of N-Al co-doped substrates were evaluated by synchrotron radiation X-ray topography (SXRT). In addition, epitaxial growth was performed on the N-Al co-doped substrates by chemical vapor deposition (CVD). No double Shockley type stacking fault was observed in the epitaxial layer.

Studies of the Distribution of Elementary Threading Screw Dislocations in 4H Silicon Carbide Wafer

2008 ◽  
Vol 600-603 ◽  
pp. 301-304 ◽  
Author(s):  
Yi Chen ◽  
Ning Zhang ◽  
Xian Rong Huang ◽  
David R. Black ◽  
Michael Dudley
Keyword(s):  
Silicon Carbide ◽  
Grazing Incidence ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Screw Dislocations ◽  
X Ray ◽  
Pyramidal Plane

The density and sense distribution of elementary threading screw dislocations in a physical vapor transport grown 3-inch 4H silicon carbide wafer have been studied. The density of TSDs ranges between 1.6×103/cm2 and 7.1×103/cm2 and the lowest density is observed at positions approximately half radius off the wafer center. The dislocation sense of elementary threading screw dislocations can be readily revealed by the asymmetric contrast of their images in grazing-incidence x-ray topographs using pyramidal plane reflections. The circumferential and radial distributions of the sense of elementary threading screw dislocations have been studied and no clear trends are observed in either distribution.

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