Hybrid quantum-classical simulation of SiC oxidation process by a wide-range search of phase space

2018 Fiscal Year Final Research Report

• Project/Area Number: 16H03830
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Nanomaterials chemistry
• Research Institution: National Institute for Materials Science
• Principal Investigator: Ohno Takahisa 国立研究開発法人物質・材料研究機構, 国際ナノアーキテクトニクス研究拠点, NIMS招聘研究員 (30344435)
• Co-Investigator(Kenkyū-buntansha): 泉 聡志 東京大学, 大学院工学系研究科(工学部), 教授 (30322069)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: ナノ材料 / 計算物理 / 表面・界面物性

Outline of Final Research Achievements

Silicon carbide (SiC) is an attractive semiconductor material for applications in power electronic devices. The atomistic mechanism of the thermal oxidation of SiC is strongly required to fabricate a high-quality SiC/SiO2 interface. We have performed DFT calculations of SiC oxidation at finite temperature and found out several elementary oxidation processes including the formation of sp2-bonded carbon clusters near the SiC/SiO2 interface, which generate electrically active states in the SiC energy gap. In order to perform long-term simulations, a Si-O-C interatomic potential of the hybrid charge-transfer type has been developed by using our DFT calculations as the training data. Using this newly developed potential, we have performed large-scale SiC oxidation simulations at various temperatures and shown that the activation energy of the Si-face is much larger than that of the C-face, which is consistent with the experimental results.

Free Research Field

計算物性科学

Academic Significance and Societal Importance of the Research Achievements

本研究により得られた炭化ケイ素（SiC）の酸化過程、SiC/SiO2界面構造、欠陥準位などに関する原子レベルでの知見は、SiCパワーデバイス開発における重要な技術課題であるSiC/SiO2界面近傍の欠陥準位の制御と低減に繋がるものと考える。また、量子論と古典論をハイブリッドした解析手法が界面特性の解析に有効であることが示され、今後、様々な界面系への展開が期待される。