scholarly journals Direct Visualization of Kinetic Reversibility of Crystallization and Dissolution Behavior at Solution Growth Interface of SiC in Si-Cr Solvent

2021 ◽  
pp. 101664
Author(s):  
Kota Nakano ◽  
Shingo Maruyama ◽  
Tomohisa Kato ◽  
Yoshiyuki Yonezawa ◽  
Hajime Okumura ◽  
...  
Keyword(s):  
Solution Growth ◽  
Dissolution Behavior ◽  
Direct Visualization ◽  
Growth Interface

Top-Seeded Solution Growth of 3 Inch Diameter 4H-SiC Bulk Crystal Using Metal Solvents

2014 ◽  
Vol 778-780 ◽  
pp. 79-82 ◽  
Author(s):  
Kazuhiko Kusunoki ◽  
Kazuhito Kamei ◽  
Nobuhiro Okada ◽  
Koji Moriguchi ◽  
Hiroshi Kaido ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Growth Process ◽  
Single Crystal Growth ◽  
Solution Growth ◽  
Process Conditions ◽  
Process Stability ◽  
Growth Interface ◽  
Formation Technique ◽  
Top Seeded Solution Growth

We performed top-seeded solution growth of 4H-SiC for obtaining longer length crystal. Si-Cr and Si-Ti melts were used as solvents. Meniscus formation technique was applied to the present study. Special attention was paid to improve the process stability during long-term growth. One of major technological problems in the solution growth is that the precipitation of polycrystalline SiC which hiders the stable single crystal growth. Another problem is the fluctuation of supersaturation at the growth interface during the growth. Through the optimization of growth process conditions, we have successfully grown 4H-SiC single crystals up to 14 mm long with three-inch-diameter, and evaluated their crystalline quality.

Growth and Characterization of CdZnTe Bulk Crystals Grown by Temperature Gradient Solution Growth

2013 ◽  
Vol 634-638 ◽  
pp. 2470-2474 ◽  
Author(s):  
Xiao Xiang Sun ◽  
Jia Hua Min ◽  
Xiao Yan Liang ◽  
Tao Zhang ◽  
Jia Qi Teng ◽  
...  
Keyword(s):  
Temperature Gradient ◽  
Growth Temperature ◽  
Optical Microscope ◽  
Solution Growth ◽  
Bulk Crystals ◽  
Growth Interface ◽  
Transmission Spectroscopy ◽  
Gradient Solution ◽  
Te Inclusions

CdZnTe bulk crystals were grown by temperature gradient solution growth (TGSG) method with the lower starting growth temperature of 1223K, temperature gradient of 20-30 K/cm and a crucible dropping rate varied from 1 to 0.6 mm/h. Optical microscope, IR microscope, I-V characteristics and FTIR transmission spectroscopy were employed to analyze the growth interfaces, Te inclusions, resistivity and IR transmittance respectively. The results indicate that a smooth and uniform growth interface has been achieved. The density of Te inclusions is about 7.9-9.5×103cm-2, while the resistivity is higher than 6.87×109Ωcm and the IR transmittance is about 55-60%.

Solution Growth of SiC Crystal with High Growth Rate Using Accelerated Crucible Rotation Technique

2006 ◽  
Vol 527-529 ◽  
pp. 119-122 ◽  
Author(s):  
Kazuhiko Kusunoki ◽  
Kazuhito Kamei ◽  
Nobuhiro Okada ◽  
Nobuyoshi Yashiro ◽  
Akihiro Yauchi ◽  
...  
Keyword(s):  
Growth Rate ◽  
High Growth ◽  
Graphite Crucible ◽  
High Growth Rate ◽  
Solution Growth ◽  
Growth Interface ◽  
Rotation Technique ◽  
Stable Growth ◽  
Crucible Rotation ◽  
Carbon Transport

We performed solution growth of SiC single crystals from Si-Ti-C ternary solution using the accelerated crucible rotation technique (ACRT). It was confirmed that the growth rate exceeding 200 μm/hr was achievable by several ACRT conditions. This high growth rate might be due to the enhancement of the carbon transport from the graphite crucible to the growth interface using the ACRT. Moreover, the incorporation of inclusions of the Si-Ti solvent in the grown crystal was significantly suppressed by using the ACRT. It was thought that the intensive convection near the growth interface resulted in not only the marked increase of SiC growth rate but also the superior homogeneity in the surface morphology. It was concluded that faster stable growth can be accomplished in the SiC solution growth using the ACRT.

Control of Interface Shape by Non-Axisymmetric Solution Convection in Top-Seeded Solution Growth of SiC Crystal

2015 ◽  
Vol 821-823 ◽  
pp. 18-21 ◽  
Author(s):  
Daiki Koike ◽  
Tomonori Umezaki ◽  
Kenta Murayama ◽  
Kenta Aoyagi ◽  
S. Harada ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Flow Direction ◽  
Solution Growth ◽  
Interface Shape ◽  
Solution Flow ◽  
Growth Interface ◽  
Axisymmetric Solution ◽  
3 Dimensional ◽  
Unidirectional Flow ◽  
Top Seeded Solution Growth

We achieved the convex growth interface shape in top-seeded solution growth of SiC applying non-axisymmetric solution convection induced by non-axisymmetric temperature distribution. The detailed solution flow, temperature distribution and carbon concentration distribution were calculated by 3-dimensional numerical analysis. In the present case, the solution flow below the crystal was unidirectional and the supersaturation was increased along the solution flow direction. By the rotation of the crystal in the unidirectional flow and the temperature distribution, we successfully obtained the crystal with the convex growth interface shape.

scholarly journals Improvement of Growth Interface Stability for 4-Inch Silicon Carbide Crystal Growth in TSSG

Crystals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 653 ◽  
Author(s):  
Botao Liu ◽  
Yue Yu ◽  
Xia Tang ◽  
Bing Gao
Keyword(s):  
Silicon Carbide ◽  
Crystal Growth ◽  
Flow Field ◽  
Industrial Production ◽  
Solution Growth ◽  
Interface Instability ◽  
Growth Interface ◽  
Interface Stability ◽  
Large Size ◽  
Top Seeded Solution Growth

The growth interface instability of large-size SiC growth in top-seeded solution growth (TSSG) is a bottleneck for industrial production. The authors have previously simulated the growth of 4-inch SiC crystals and found that the interface instability in TSSG was greatly affected by the flow field. According to our simulation of the flow field, we proposed a new stepped structure that greatly improved the interface stability of large-size crystal growth. This stepped structure provides a good reference for the growth of large-sized SiC crystals by TSSG in the future.

Analysis of the Spiral Step Structure and the Initial Solution Growth Behavior of SiC by Real-Time Observation of the Growth Interface

2016 ◽  
Vol 16 (9) ◽  
pp. 4822-4830 ◽  
Author(s):  
Sakiko Kawanishi ◽  
Masao Kamiko ◽  
Takeshi Yoshikawa ◽  
Yoshitaka Mitsuda ◽  
Kazuki Morita
Keyword(s):  
Real Time ◽  
Growth Behavior ◽  
Initial Solution ◽  
Solution Growth ◽  
Growth Interface ◽  
Step Structure ◽  
Time Observation ◽  
Real Time Observation

Increase in the Growth Rate by Rotating the Seed Crystal at High Speed during the Solution Growth of SiC

2014 ◽  
Vol 778-780 ◽  
pp. 63-66 ◽  
Author(s):  
Tomonori Umezaki ◽  
Daiki Koike ◽  
Atsushi Horio ◽  
S. Harada ◽  
Toru Ujihara
Keyword(s):  
Numerical Simulation ◽  
Growth Rate ◽  
Carbon Concentration ◽  
Concentration Gradient ◽  
High Speed ◽  
Rotation Speed ◽  
Seed Crystal ◽  
Solution Growth ◽  
Growth Interface ◽  
Wide Range

We studied the effect of rotation speed of seed crystal on the growth rate during the solution growth of SiC. The growth rate increased with increasing rotation speed of the seed crystal. The increase in the growth rate was observed in relatively wide range of carbon concentration. According to the numerical simulation, the carbon concentration gradient near the growth interface under 150 rpm condition is larger than 20 rpm (ACRT) condition. This indicates that increase in the growth rate is caused by the increase in the carbon concentration gradient of the diffusion layer.

Solution Growth of Single Crystalline 6H-SiC from Si-Ti-C Ternary Solution

2007 ◽  
Vol 352 ◽  
pp. 89-94 ◽  
Author(s):  
Kenji Suzuki ◽  
Kazuhiko Kusunoki ◽  
Nobuyoshi Yashiro ◽  
Nobuhiro Okada ◽  
Kazuhito Kamei ◽  
...  
Keyword(s):  
Growth Rate ◽  
Single Crystal ◽  
High Growth ◽  
Graphite Crucible ◽  
High Growth Rate ◽  
Solution Growth ◽  
Ternary Solution ◽  
X Ray Diffraction ◽  
Growth Interface ◽  
X Ray

Solution growth of 6H-SiC single crystal from Si-Ti-C ternary solution using the accelerated crucible rotation technique (ACRT) was performed. The SiC growth rate exceeding 200 μm/hr was achieved in several ACRT conditions. Such a high growth rate can be ascribed to the enhancement of the carbon transport from the graphite crucible to the growth interface due to the use of the ACRT. The incorporation of inclusions of Si-Ti solvent in the grown SiC crystal was also significantly suppressed by using the ACRT. The intensive convection near the growth interface induced by the ACRT resulted in not only the marked increase of SiC growth rate but also the superior homogeneity in the surface morphology. It was concluded that faster stable growth could be accomplished in the SiC solution growth using the ACRT. The obtained SiC self-standing crystal exhibited homogeneous green colour without cracks and inclusions. We investigated the crystalline quality of the grown SiC crystal by means of X-ray diffraction. The, ω-scan rocking curves of (0006) reflection measured by X-ray diffraction provided the FWHM of 15-20 arc-second showing the excellent crystallinity of the solution grown 6H-SiC single crystal.

Direct visualization of phase-separated domains in lipid membranes

1978 ◽  
Vol 36 (2) ◽  
pp. 290-291
Author(s):  
S. W. Hui ◽  
T. P. Stewart
Keyword(s):  
Lipid Membranes ◽  
Structural Information ◽  
Freeze Fracture ◽  
Biological Molecules ◽  
Vacuum Drying ◽  
Direct Visualization ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
X Ray ◽  
Hydrocarbon Chains

Direct electron microscopic study of biological molecules has been hampered by such factors as radiation damage, lack of contrast and vacuum drying. In certain cases, however, the difficulties may be overcome by using redundent structural information from repeating units and by various specimen preservation methods. With bilayers of phospholipids in which both the solid and fluid phases co-exist, the ordering of the hydrocarbon chains may be utilized to form diffraction contrast images. Domains of different molecular packings may be recgnizable by placing properly chosen filters in the diffraction plane. These domains would correspond to those observed by freeze fracture, if certain distinctive undulating patterns are associated with certain molecular packing, as suggested by X-ray diffraction studies. By using an environmental stage, we were able to directly observe these domains in bilayers of mixed phospholipids at various temperatures at which their phases change from misible to inmissible states.

Sign in / Sign up

Export Citation Format

Share Document