Fast growth of n-type 4H-SiC bulk crystal by gas-source method

Limitations in the very fast growth of 4H-SiC crystals are surveyed for a high-temperature gas source method. The evolution of macro-step bunching and void formation in crystal growth is investigated by changing the partial pressures of the source gases and crystal rotation speeds. The variation in macro-step formation depending on radial positions, where step-flow or spiral growth governs, of a grown crystal is also revealed. Based on the relation between growth conditions and macro-step bunching, a trade-off between growth rate enhancement and crystal quality and a method to improve such trade-off are discussed. Nitrogen at a high concentration under very high growth rates in the high-temperature gas source method is also investigated.

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Fast 4H-SiC Bulk Growth by High-Temperature Gas Source Method

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1004.5 ◽

2020 ◽

Vol 1004 ◽

pp. 5-13

Author(s):

Yuichiro Tokuda ◽

Norihiro Hoshino ◽

Hironari Kuno ◽

Hideyuki Uehigashi ◽

Takeshi Okamoto ◽

...

Keyword(s):

Growth Rate ◽

Crystal Growth ◽

High Temperature ◽

Gas Flow ◽

Fast Growth ◽

Process Conditions ◽

Bulk Growth ◽

Source Method ◽

Gas Source ◽

High Temperature Gas

The process conditions for fast growth of 4 in. 4H-polytype SiC (4H-SiC) single crystals were studied for high-temperature gas source method. Prior to experiments, crystal growth simulations were conducted to investigate the influence of vertical gas-flow velocity on the radial distribution of the growth rate. Crystal growth experiments were performed using the crucibles designed for 4 in. crystal growth following the simulation studies. By investigating growth rate as functions of the input partial pressure of source gases and temperatures of growing surfaces, expressions for the growth rate of 4-in. crystals were derived. We also clarified the optimal conditions for single-crystal growth. Finally, fast growth of 4 in. 4H-SiC crystals with uniform shape was demonstrated.

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Reduction in dislocation densities in 4H-SiC bulk crystal grown at high growth rate by high-temperature gas-source method

Applied Physics Express ◽

10.35848/1882-0786/abace0 ◽

2020 ◽

Vol 13 (9) ◽

pp. 095502

Author(s):

Norihiro Hoshino ◽

Isaho Kamata ◽

Takahiro Kanda ◽

Yuichiro Tokuda ◽

Hironari Kuno ◽

...

Keyword(s):

Growth Rate ◽

High Temperature ◽

High Growth ◽

High Growth Rate ◽

Bulk Crystal ◽

Source Method ◽

Gas Source ◽

Dislocation Densities ◽

High Temperature Gas

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Enhancement of Single-Walled Carbon Nanotube Formation Using Aluminum Oxide Buffer Layer in Alcohol Gas Source Method

10.1557/proc-1142-jj05-07 ◽

2008 ◽

Author(s):

Takahiro Maruyama ◽

Tomoyuki Shiraiwa ◽

Kuninori Sato ◽

Shigeya Naritsuka

Keyword(s):

Carbon Nanotube ◽

Aluminum Oxide ◽

Buffer Layer ◽

Single Walled Carbon Nanotube ◽

Single Walled Carbon ◽

Source Method ◽

Gas Source

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Low Temperature Growth of Single-Walled Carbon Nanotubes from Pt Catalysts under Low Ethanol Pressure by Alcohol Gas Source Method

Journal of Nanotechnology ◽

10.1155/2012/690304 ◽

2012 ◽

Vol 2012 ◽

pp. 1-5 ◽

Cited By ~ 6

Author(s):

Hiroki Kondo ◽

Naoya Fukuoka ◽

Takahiro Maruyama

Keyword(s):

Carbon Nanotubes ◽

High Vacuum ◽

Single Walled Carbon Nanotubes ◽

Average Diameter ◽

Diameter Distribution ◽

Pt Catalysts ◽

Single Walled Carbon ◽

Source Method ◽

Gas Source ◽

Walled Carbon Nanotubes

Growth of single-walled carbon nanotubes (SWNTs) was carried out on SiO2/Si substrates with Pt catalysts at 400, 450, and 700°C under various ethanol pressures using an alcohol gas source method in a high vacuum, and the grown SWNTs were characterized by scanning electron microscopy (SEM) and Raman spectroscopy. Irrespective of the growth temperature, both G band and RBM peaks were observed in the Raman spectra under the optimal ethanol pressure (~1×10−3Pa), indicating that SWNTs grew below 450°C from Pt. At 400°C, both average diameter and diameter distribution were drastically reduced, and those were fairly smaller and narrower, compared to those for SWNTs grown with Co.

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