The Effect of Modified Crucible Design and Seed Attachment on SiC Crystal Grown by PVT

2013 ◽  
Vol 740-742 ◽  
pp. 77-80
Author(s):  
Jung Young Jung ◽  
Sang Il Lee ◽  
Mi Seon Park ◽  
Doe Hyung Lee ◽  
Hee Tae Lee ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Temperature Gradient ◽  
Single Crystals ◽  
Crystal Quality ◽  
Full Width ◽  
Half Maximum ◽  
Radial Temperature Gradient ◽  
Radial Temperature ◽  
Better Than

The present research was focused to investigate the effect of internal crucible design that influenced the 4H-SiC crystal growth onto a 6H-SiC seed by PVT method. The crucible design was modified to produce a uniform radial temperature gradient in the growth cell. The seed attachment was also modified with a use of polycrystalline SiC plate. The crystal quality of 4H-SiC single crystals grown in modified crucible and grown with modified seed attachment was revealed to be better than that of crystal grown in conventional crucible. The full width at half maximum (FWHM) values of grown SiC crystals in the conventional crucible, the modified seed attachment and the modified crucible were 285 arcsec, 134 arcsec and 128 arcsec, respectively. The micropipe density (MPD) of grown SiC crystals in the conventional crucible, the modified seed attachment and the modified crucible were 101ea/cm^2, 81ea/cm^2 and 42ea/cm^2, respectively.

scholarly journals Homogenization of Radial Temperature by a Tungsten Sink in Sublimation Growth of 45 mm AlN Single Crystal

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5553
Author(s):  
Yue Yu ◽  
Botao Liu ◽  
Xia Tang ◽  
Sheng Liu ◽  
Bing Gao
Keyword(s):  
Thermal Stress ◽  
Crystal Growth ◽  
Heat Exchange ◽  
Single Crystal ◽  
Numerical Experiments ◽  
Radial Temperature Gradient ◽  
Radial Temperature ◽  
Large Size ◽  
Sublimation Growth

To reduce the thermal stress during the sublimation growth of 45 mm AlN single crystal, a tungsten sink was put on the top of the crucible lid. Numerical experiments showed that the radial temperature gradient was reduced due to the homogenization effect on temperature as a result of the sink. Therefore, this simple tungsten sink method has the potential to grow large-size AlN ingots with fewer cracks. It also reveals that enhancing the heat exchange of the crucible lid is an effective way to improve the quality of crystal growth.

Effect of Porous Graphite for High Quality SiC Crystal Growth by PVT Method

2015 ◽  
Vol 821-823 ◽  
pp. 43-46 ◽  
Author(s):  
Hee Jun Lee ◽  
Hee Tae Lee ◽  
Hee Won Shin ◽  
Mi Seon Park ◽  
Yeon Suk Jang ◽  
...  
Keyword(s):  
Source Material ◽  
Vapor Transport ◽  
Radial Temperature Gradient ◽  
Dendrite Structure ◽  
Radial Temperature ◽  
Graphite Plate ◽  
Porous Graphite ◽  
Transport Method ◽  
Better Than

The effect of the porous graphite plate above the source material on properties of silicon carbide (SiC) crystals grown by Physical Vapor Transport method has been investigated. The porous graphite plate was inserted on source powder to produce a more C-rich for the polytype stability of 4H-SiC crystal and a uniform radial temperature gradient. The dendrite structure obtained from SiC source powder in the crucible with porous graphite plate was more densely formed than that in the conventional crucible. The crystal quality of 4H-SiC single crystals grown in porous graphite inserted crucible was revealed to be better than that of crystal grown SiC crystals in the conventional crucible.

Non-Polar SiC Crystal Growth with m-Plane(1-100) and a-Plane(11-20) by PVT Method

2010 ◽  
Vol 645-648 ◽  
pp. 37-40
Author(s):  
Im Gyu Yeo ◽  
Tae Woo Lee ◽  
Won Jae Lee ◽  
Byoung Chul Shin ◽  
Il Soo Kim ◽  
...  
Keyword(s):  
Raman Spectrum ◽  
Crystal Growth ◽  
Carrier Concentration ◽  
Basal Plane ◽  
Stacking Faults ◽  
Full Width ◽  
Half Maximum ◽  
Etch Pits ◽  
Koh Etching

The present research was focused to produce 2 inch wafers from small rectangular seeds and to investigate the quality of non-polar SiC substrates grown by a conventional PVT method. The non-polar SiC seeds were prepared by cutting along <0001> direction of 6H-SiC crystal grown on (0001) basal plane. As SiC ingot grows, many defects in connected region were gradually diminished. While the full width at half maximum (FWHM) values of m-plane SiC substrate measured along a-direction and c-direction were 60 arcsec and 70 arcsec, respectively, and the FWHM values of a-plane SiC substrate measured along m-direction and c-direction were 27 arcsec and 31 arcsec respectively. The stacking faults lying in the basal plane can be detected by molten KOH etching as linear etch pits extending along <0001> on the (11-20) surface and the carrier concentration was observed by Raman spectrum.

Polytype Control by Pretreatment of SiC Source Powder for 4H-SiC Single Crystal Growth

2019 ◽  
Vol 963 ◽  
pp. 38-41
Author(s):  
Jung Woo Choi ◽  
Jung Gyu Kim ◽  
Byung Kyu Jang ◽  
Sang Ki Ko ◽  
Myung Ok Kyun ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Carbon Source ◽  
Single Crystal ◽  
Single Crystal Growth ◽  
Crystal Quality ◽  
Liquid Carbon ◽  
Source Power ◽  
Better Than

4H-SiC single crystal was successfully grown with source powder modified by the pretreatment process in order to improve polytype stability of SiC crystal. To increase C/Si ratio in SiC source powder, SiC source powder was mixed with liquid carbon source and then pre-heated at 1200°C. SiC single crystal grown with modified source powder exhibited complete 4H polytype and the crystal quality of SiC crystal grown by modified source power was definitely better than conventional source powder

New Materials for Semi-Insulating SiC Single Crystal Growth by PVT Method

2019 ◽  
Vol 963 ◽  
pp. 46-50
Author(s):  
Jeong Min Choi ◽  
Chae Young Lee ◽  
Dae Sung Kim ◽  
Mi Seon Park ◽  
Yeon Suk Jang ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Single Crystal ◽  
Single Crystal Growth ◽  
Crystal Quality ◽  
New Materials ◽  
Graphite Plate ◽  
Porous Graphite ◽  
Better Than

The present research was focused on the effect of porous graphite plate in TaC-coated crucible on crystal quality and resistivity of semi-insulating SiC crystals. Two SiC crystals grown with/without porous graphite plate in TaC-coated crucible were systematically compared. 6H-SiC polytype was obtained on both crystals regardless of porous graphite plate. The quality of SiC crystal grown using porous graphite plate placed in the TaC-coated crucible was slightly better than SiC crystal without porous graphite plate. SiC crystals having an average resistivity value of about 1×1010 Ωcm were obtained. In the result of COREMA measurement, the use of porous graphite plate tends to obtain wafers with better uniformity in resistivity value.

scholarly journals The Physical Vapor Transport Method for Bulk AlN Crystal Growth

Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1562 ◽  
Author(s):  
Wen-Hao Chen ◽  
Zuo-Yan Qin ◽  
Xu-Yong Tian ◽  
Xu-Hui Zhong ◽  
Zhen-Hua Sun ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Temperature Gradient ◽  
Single Crystals ◽  
Low Cost ◽  
Vapor Transport ◽  
Physical Vapor Transport ◽  
Inverse Temperature ◽  
Seeded Growth ◽  
Perforated Sheet

In this report, the development of physical vapor transport (PVT) methods for bulk aluminum nitride (AlN) crystal growth is reviewed. Three modified PVT methods with different features including selected growth at a conical zone, freestanding growth on a perforated sheet, and nucleation control with an inverse temperature gradient are discussed and compared in terms of the size and quality of the bulk AlN crystals they can produce as well as the process complexity. The PVT method with an inverse temperature gradient is able to significantly reduce the nucleation rate and realize the dominant growth of only one bulk AlN single crystal, and thus grow centimeter-sized bulk AlN single crystals. X-ray rocking curve (XRC) and Raman spectroscopy measurements showed a high crystalline quality of the prepared AlN crystals. The inverse temperature gradient provides an efficient and relatively low-cost method for the preparation of large-sized and high-quality AlN seed crystals used for seeded growth, devoted to the diameter enlargement and quality improvement of bulk AlN single crystals.

scholarly journals InP nanowires quality control using SEM and Raman spectroscopy

2016 ◽  
Vol 34 (4) ◽  
pp. 851-855
Author(s):  
K. Grodecki ◽  
E. Dumiszewska ◽  
M. Romaniec ◽  
W. Strupinski
Keyword(s):  
Raman Spectroscopy ◽  
Low Energy ◽  
Crystal Quality ◽  
Full Width ◽  
Half Maximum ◽  
Sem Images ◽  
Different Types ◽  
Si Doped ◽  
Scanning Electron

AbstractThree different types of samples of InP nanowires, i.e. undoped, doped with Si and doped with Te, were grown and measured using SEM and Raman spectroscopy. Scanning Electron Microscope (SEM) images showed differences in the length, homogeneity and curvature of the nanowires. The most homogenous wires, grown most perpendicular to the surface, were those Si doped. They were also the shortest. Raman spectroscopy showed that the nanowires doped with Si had the lowest Full Width at Half Maximum (FWHM) TO band, which suggests the highest crystal quality of these wires. For the wires doped with Te, which were the most inhomogeneous, a low energy acoustic band was also observed, which suggests the lowest crystal quality of these structures.

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