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.

Improvement of Surface Morphology by Solution Flow Control in Solution Growth of SiC on Off-Axis Seeds

2015 ◽  
Vol 821-823 ◽  
pp. 31-34 ◽  
Author(s):  
Tomonori Umezaki ◽  
Daiki Koike ◽  
S. Harada ◽  
Toru Ujihara
Keyword(s):  
Flow Direction ◽  
Seed Crystal ◽  
Solution Growth ◽  
Rotational Axis ◽  
Solution Flow ◽  
Step Flow ◽  
Unidirectional Flow ◽  
Novel Method ◽  
Set Up ◽  
Top Seeded Solution Growth

The solution growth of SiC on an off-axis seed is effective on the reduction of threading dislocations. We proposed a novel method to grow a SiC crystal on an off-axis seed by top-seeded solution growth (TSSG). In our previous study, a unidirectional solution flow above a seed crystal is effective to suppress surface roughness in the growth on the off-axis seed. However, it is difficult to apply the unidirectional flow in an axisymmetric TSSG set-up. In this study, the unidirectional flow could be achieved by shifting the rotational axis away from the center of the seed crystal. As a result, the smooth surface was obtained in the wider area where the solution flow direction was opposite to the step-flow direction.

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.

Effect of Solution Drift on Crystalline Morphology in the Solution Growth of Off-Axis 4H-SiC Crystals

2016 ◽  
Vol 858 ◽  
pp. 65-68
Author(s):  
Takashi Kato ◽  
Kazuhiko Kusunoki ◽  
Kazuaki Seki ◽  
Nobuhiro Okada ◽  
Kazuhito Kamei
Keyword(s):  
Surface Morphology ◽  
Flow Direction ◽  
Solute Concentration ◽  
The Other ◽  
Solution Growth ◽  
Morphological Stability ◽  
Crystalline Morphology ◽  
Solution Flow ◽  
Step Flow ◽  
Flow Directions

We investigated the effect of the solution flow on crystalline morphology in the off-axis 4H-SiC solution growth. In particular, we focused on the relation between the Si solution flow and step flow directions. In step parallel flow in which the solution drifted transversely to the step flow direction of the off-axis substrate, it was possible to attain a better surface morphology than in the flow in which the solution drifted toward the other direction. Furthermore, it was found that the surface morphology was found to be improved as the solution flow velocity increased. These improvements in the morphological stability are presumed to be caused by aligning the solute concentration fluctuation along the steps.

Influences of Solution Flow and Lateral Temperature Distribution on Surface Morphology in Solution Growth of SiC

2015 ◽  
Vol 821-823 ◽  
pp. 35-38
Author(s):  
Kuniharu Fujii ◽  
Koichi Takei ◽  
Masahiro Aoshima ◽  
Nachimuthu Senguttuvan ◽  
Masahiko Hiratani ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Temperature Gradient ◽  
Surface Morphology ◽  
Rotation Rate ◽  
Flat Surface ◽  
Growth Front ◽  
Solution Growth ◽  
Solution Flow ◽  
Graphite Rod ◽  
Lateral Temperature

The influences of solution flow and lateral temperature distribution on the surface morphology of the 4H-SiC single crystal grown from solution was investigated. A flat surface region was enlarged by the seed-rotation rate. The solution flow simulation indicated that the higher rotation rate made the outward solution flow ordered beneath the solution surface. Such a solution flow was thought to be effective to enlarge the flat region of growth front. Furthermore, a full-flat surface was obtained with a hollow-type graphite rod at a seed-rotation rate of 60 min-1. The simulated results of temperature distribution showed the hollow-type graphite rod reduced the lateral temperature gradient at the SiC-solution interface. The ordered solution flow and the small temperature gradient at the growth front were found to be effective to make the growth front flat in the solution-growth method.

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.

The Effect of Stepped Wall of the Graphite Crucible in Top Seeded Solution Growth of SiC Crystal

2018 ◽  
Vol 924 ◽  
pp. 27-30
Author(s):  
Su Hun Choi ◽  
Young Gon Kim ◽  
Yun Ji Shin ◽  
Seong Min Jeong ◽  
Myung Hyun Lee ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Growth Rate ◽  
Temperature Distribution ◽  
Optical Microscopy ◽  
Single Crystals ◽  
Carbon Concentration ◽  
Graphite Crucible ◽  
Solution Growth ◽  
Metal Addition ◽  
Top Seeded Solution Growth

The crucible design having a stepped wall was introduced for increasing the growth rate of SiC crystal without metal addition in top-seeded solution growth (TSSG) method. The numerical simulation confirmed that new crucible design to increase the solvent-crucible interface could definitely change the temperature distribution and increase the carbon concentration. The simulation result, SiC single crystals were grown with Si solvent at 1900°C using a normal crucible and a stepped crucible to investigate the effect of crucible design having a stepped wall. Grown SiC layers were analyzed using Optical microscopy and Raman spectra. The growth rate in the stepped crucible was finally 66um/h observed.

YMgB5O10 crystal preparation and attractive multi-wavelength emission characteristics of doping Nd3+ ions

2021 ◽  
Author(s):  
Shijia Sun ◽  
Qi Wei ◽  
Bing-Xuan Li ◽  
Xingjun Shi ◽  
feifei yuan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Transmission Spectrum ◽  
Systematic Investigation ◽  
Solution Growth ◽  
Emission Characteristics ◽  
Multi Wavelength ◽  
Growth Method ◽  
Wavelength Emission ◽  
Spectrum Band ◽  
Top Seeded Solution Growth

The pure and Nd3+-doped YMgB5O10 (YMB, Nd:YMB) crystals were grown successfully by the top-seeded solution growth method with composite fluxes Li2O-B2O3-LiF. The systematic investigation of crystal structure, transmission spectrum, band...

Growth of Ti alloyed Nb3Sn crystals from Sn-Ti-Nb solutions by top seeded solution growth

1986 ◽  
Vol 78 (3) ◽  
pp. 567-570 ◽  
Author(s):  
T. Inoue ◽  
H. Komatsu ◽  
M. Shimizu ◽  
S. Tsunekawa ◽  
H. Takei
Keyword(s):  
Solution Growth ◽  
Top Seeded Solution Growth
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