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Title: Short-pulse excitation of microwave plasma for efficient diamond growth

Abstract

To realize a variety of potential applications of diamonds, particularly in the area of power electronics, it is indispensable to improve their growth efficiency. Most conventional approaches have tried to achieve this simply by increasing the gas temperature; however, this makes it difficult to grow large diamond crystals. To improve the growth efficiency while lowering the gas temperature, we propose that using a pulse-modulated microwave plasma with a sub-millisecond pulse width can enhance the power efficiency of the growth rate of single-crystal diamonds. We found that using a sub-millisecond pulse-mode discharge could almost double the growth rate obtained using continuous mode discharge for a fixed average microwave power and gas pressure. A comparison between experimental observations of the optical emission spectra of the discharge and a numerical simulation of the gas temperature suggests that a decrease in the gas temperature was achieved, and highlights the importance of electron-dominated reactions for obtaining the enhancement of the growth rate. This result will have a large impact in the area of diamond growth because it enables diamond growth to be more power efficient at reduced temperatures.

Authors:
; ;  [1]
  1. Advanced Power Electronics Research Center (ADPERC), National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 (Japan)
Publication Date:
OSTI Identifier:
22590498
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 109; Journal Issue: 9; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; DIAMONDS; EFFICIENCY; EXCITATION; MICROWAVE RADIATION; MONOCRYSTALS; PLASMA; PULSES

Citation Formats

Yamada, Hideaki, E-mail: yamada-diamond@aist.go.jp, Chayahara, Akiyoshi, and Mokuno, Yoshiaki. Short-pulse excitation of microwave plasma for efficient diamond growth. United States: N. p., 2016. Web. doi:10.1063/1.4962218.
Yamada, Hideaki, E-mail: yamada-diamond@aist.go.jp, Chayahara, Akiyoshi, & Mokuno, Yoshiaki. Short-pulse excitation of microwave plasma for efficient diamond growth. United States. doi:10.1063/1.4962218.
Yamada, Hideaki, E-mail: yamada-diamond@aist.go.jp, Chayahara, Akiyoshi, and Mokuno, Yoshiaki. 2016. "Short-pulse excitation of microwave plasma for efficient diamond growth". United States. doi:10.1063/1.4962218.
@article{osti_22590498,
title = {Short-pulse excitation of microwave plasma for efficient diamond growth},
author = {Yamada, Hideaki, E-mail: yamada-diamond@aist.go.jp and Chayahara, Akiyoshi and Mokuno, Yoshiaki},
abstractNote = {To realize a variety of potential applications of diamonds, particularly in the area of power electronics, it is indispensable to improve their growth efficiency. Most conventional approaches have tried to achieve this simply by increasing the gas temperature; however, this makes it difficult to grow large diamond crystals. To improve the growth efficiency while lowering the gas temperature, we propose that using a pulse-modulated microwave plasma with a sub-millisecond pulse width can enhance the power efficiency of the growth rate of single-crystal diamonds. We found that using a sub-millisecond pulse-mode discharge could almost double the growth rate obtained using continuous mode discharge for a fixed average microwave power and gas pressure. A comparison between experimental observations of the optical emission spectra of the discharge and a numerical simulation of the gas temperature suggests that a decrease in the gas temperature was achieved, and highlights the importance of electron-dominated reactions for obtaining the enhancement of the growth rate. This result will have a large impact in the area of diamond growth because it enables diamond growth to be more power efficient at reduced temperatures.},
doi = {10.1063/1.4962218},
journal = {Applied Physics Letters},
number = 9,
volume = 109,
place = {United States},
year = 2016,
month = 8
}
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