Structural and Electrical Characterization of the Initial Stage of Physical Vapor Transport Growth of 4H-SiC Crystals

2015 ◽  
Vol 821-823 ◽  
pp. 90-95
Author(s):  
Tatsuya Takahashi ◽  
Chikashi Ohshige ◽  
Noboru Ohtani ◽  
Masakazu Katsuno ◽  
Tatsuo Fujimoto ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Grown Crystal ◽  
Defect Formation ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Formation Mechanisms ◽  
X Ray Diffraction ◽  
X Ray ◽  
Initial Stage ◽  
Crystal Seed

Defect formation during the initial stage of physical vapor transport (PVT) growth of 4H-SiC crystals in the [000-1] and [11-20] directions was investigated by x-ray diffraction, defect-selective etching, and micro Raman scattering imaging. X-ray diffraction studies showed that the growths in the [000-1] and [11-20] directions exhibited markedly different behaviors with respect to the defect formation during the initial stage of growth. While a characteristic lattice plane bending was observed for the PVT growth along [000-1], a tilted domain structure was revealed near the grown crystal/seed interface for the growth in the [11-20] direction. Micro Raman scattering imaging revealed that nitrogen enrichment occurred near the grown crystal/seed interface and was associated with compressive stress parallel to the interface. Based on the results, the defect formation mechanisms during the initial stage of PVT growth of 4H-SiC are discussed.

High Resolution X-Ray Diffraction (HRXRD) Studies of the Initial Stages of PVT-Growth of 4H-SiC Crystals

2012 ◽  
Vol 717-720 ◽  
pp. 489-492
Author(s):  
Noboru Ohtani ◽  
Masakazu Katsuno ◽  
T. Fujimoto ◽  
S. Sato ◽  
Hiroshi Tsuge ◽  
...  
Keyword(s):  
High Resolution ◽  
Grown Crystal ◽  
Defect Formation ◽  
Growth Direction ◽  
Vapor Transport ◽  
Formation Processes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Close Proximity ◽  
Crystal Interface

Defect formation during the early stages of physical vapor transport (PVT) growth of 4H-SiC was investigated using high resolution x-ray diffraction (HRXRD). Characteristic lattice bending behaviors were revealed in the nearby seed crystal regions of grown crystals. The lattice bending was localized in close proximity to the seed/grown crystal interface, and the (0001) basal planes bended convexly toward the growth direction, indicative of the insertion of extra-half planes pointing toward the growth direction during the initial stages of crystal growth. This paper discusses the possible mechanisms of the observed lattice bending and sheds light on the defect formation processes during PVT-growth of 4H-SiC single crystals.

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.

Defect formation during the initial stage of physical vapor transport growth of 4H–SiC in the[112¯0]direction

2014 ◽  
Vol 408 ◽  
pp. 1-6 ◽  
Author(s):  
Chikashi Ohshige ◽  
Tatsuya Takahashi ◽  
Noboru Ohtani ◽  
Masakazu Katsuno ◽  
Tatsuo Fujimoto ◽  
...  
Keyword(s):  
Defect Formation ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Initial Stage

scholarly journals Surface Morphology Study of Chemical Vapor Transport of ZnO Crystals

Scanning ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Long Fan ◽  
Jia Li ◽  
Dawei Yan ◽  
Liping Peng ◽  
Tao Jiang ◽  
...  
Keyword(s):  
Grown Crystal ◽  
Chemical Vapor ◽  
Optical Microscope ◽  
Vapor Transport ◽  
Chemical Vapor Transport ◽  
X Ray Diffraction ◽  
Vapor Interface ◽  
X Ray ◽  
Thermal Etching ◽  
Scanning Electron

A chemical vapor transport (CVT) method was implemented to grow bulk ZnO crystals. X-ray diffraction (XRD), field emission scanning electron microscopy (SEM), and optical microscope (OM) studies were carried out to characterize the surface properties of the grown crystal. The XRD result indicated the exposed solid-vapor interface of the as-grown crystal was composed of (0001) and {101-1} faces. Using SEM and OM, we observed small hexagonal pyramids and microstructures formed of crosslines on the as-grown crystal and found hexagonal thermal etching pits on the surfaces of seed crystals. The formation, evolution, and distribution mechanisms of the microstructures were investigated.

scholarly journals TEM Study of Bulk AlN Growth by Physical Vapor Transport

2000 ◽  
Vol 5 (S1) ◽  
pp. 384-390
Author(s):  
W.L. Sarney ◽  
L. Salamanca-Riba ◽  
T. Hossain ◽  
P. Zhou ◽  
H.N. Jayatirtha ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Auger Electron ◽  
Film Growth ◽  
Structural Characteristics ◽  
Columnar Structure ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Nitride Film ◽  
X Ray Diffraction ◽  
X Ray

We are attempting to grow bulk AlN that would be suitable as a substrate for nitride film growth. Bulk AlN films were grown by physical vapor transport on 3.5° off-axis and on-axis 6H SiC seed crystals and characterized by TEM, x-ray-diffraction, Auger electron microscopy, and SEM. TEM images show that the bulk AlN does not have the columnar structure typically seen in AlN films grown by MOCVD. Although further optimization is required before the bulk AlN is suitable as a substrate, we find that the structural characteristics achieved thus far indicate that quality bulk AlN substrates may be obtained in the future.

TEM Study of Bulk AlN Growth by Physical Vapor Transport

1999 ◽  
Vol 595 ◽  
Author(s):  
W.L. Sarney ◽  
L. Salamanca-Riba ◽  
T. Hossain ◽  
P. Zhou ◽  
H.N. Jayatirtha ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Auger Electron ◽  
Film Growth ◽  
Structural Characteristics ◽  
Columnar Structure ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Nitride Film ◽  
X Ray Diffraction ◽  
X Ray

AbstractWe are attempting to grow bulk AlN that would be suitable as a substrate for nitride film growth. Bulk AlN films were grown by physical vapor transport on 3.5° offaxis and on-axis 6H SiC seed crystals and characterized by TEM, x-ray-diffraction, Auger electron microscopy, and SEM. TEM images show that the bulk AlN does not have the columnar structure typically seen in AlN films grown by MOCVD. Although further optimization is required before the bulk AlN is suitable as a substrate, we find that the structural characteristics achieved thus far indicate that quality bulk AlN substrates may be obtained in the future.

Point Defect Behavior in B2-Type Intermetallic Compound FeAl

1998 ◽  
Vol 552 ◽  
Author(s):  
T. Haraguchi ◽  
M. Kogachi
Keyword(s):  
Point Defect ◽  
Defect Formation ◽  
Vacancy Concentration ◽  
Point Of View ◽  
Formation Mechanisms ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vacancy Distribution ◽  
Defect Behavior

ABSTRACTPoint defect behavior in B2-type FeAI alloys is investigated from a thermodynamic point of view, based on the Bragg-Williams method. The model is developed by taking new defect formation mechanisms, random vacancy distribution (RVD), and antisite atom recovering (ASAR), into consideration, which were proposed based on the current findings in in situ neutron and X-ray diffraction studies for the B2 FeAl. The condition for appearance of the RVD and ASAR states is given. Application of this model to B2 FeAl alloys shows that the RVD-like behavior is reproduced in the Ferich composition region and also a rapid increase in vacancy concentration observed in the Al-rich region can be interpreted by the ASAR process by antisite Al atoms.

Reciprocal Space Mapping Studies of the Initial Stage of the PVT Growth of 4H-SiC Crystals Parallel and Perpendicular to the c-Axis

2014 ◽  
Vol 778-780 ◽  
pp. 43-46
Author(s):  
Chikashi Ohshige ◽  
Tatsuya Takahashi ◽  
Noboru Ohtani ◽  
Masakazu Katsuno ◽  
Tatsuo Fujimoto ◽  
...  
Keyword(s):  
Grown Crystal ◽  
Defect Formation ◽  
Nitrogen Concentration ◽  
Space Mapping ◽  
Reciprocal Space ◽  
Subgrain Structure ◽  
Reciprocal Space Mapping ◽  
Initial Stage ◽  
The Difference ◽  
Crystal Seed

Defect formation during the initial stage of physical vapor transport (PVT) growth in the [000-1] and [11-20] directions has been investigated by x-ray reciprocal space mapping (RSM) and defect-selective etching. RSM studies showed that, while the crystal grown in the [000-1] direction did not show a significant degradation of the crystalline quality during the initial stage of growth, the growth in the [11-20] direction resulted in misoriented subgrain structure near the grown crystal/seed interface. The cause of the domain formation is assumed to be the difference in nitrogen concentration between the seed and the grown crystal, and the results indicate that the growth in the [11-20] direction is greatly affected by the nitrogen doping difference.

Initial Stage Modification for 6H-SiC Single Crystal Grown by the Physical Vapor Transport (PVT) Method

2009 ◽  
Vol 615-617 ◽  
pp. 7-10 ◽  
Author(s):  
Jung Woo Choi ◽  
Chang Hyun Son ◽  
Jong Mun Choi ◽  
Gi Sub Lee ◽  
Won Jae Lee ◽  
...  
Keyword(s):  
Single Crystal ◽  
Defect Formation ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Growth Step ◽  
Initial Stage ◽  
Low Rate ◽  
Main Growth

Two SiC single crystal ingots were prepared using sublimation PVT techniques through the different process procedure and then their crystal quality was systematically compared, because the present research was focused to improve the quality of SiC crystal by modifying the initial stage of the PVT growth. Before the main growth step for growing SiC bulk crystal, initial stage period where growth rate was kept to relatively low rate of <10μm/h was introduced to conventional process procedure. N-type 2”-SiC single crystals exhibiting the polytype of 6H-SiC was successfully fabricated. As compared to the characteristics of SiC crystal grown using the conventional schedule, the quality of SiC crystal grown with modifying the initial stage was significantly improved, exhibiting decrease of defect formation such as micropipe and polytype formation.

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