Study on Limiting Factors of Electron Mobility in SiC MOS Inversion Channel with Improved Quality Interface

2017 Fiscal Year Final Research Report

• Project/Area Number: 15H03969
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Electronic materials/Electric materials
• Research Institution: The University of Tokyo
• Principal Investigator: Kita Koji 東京大学, 大学院工学系研究科(工学部), 准教授 (00343145)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 電気・電子材料 / 半導体物性 / パワーデバイス / 電界効果移動度 / デバイスプロセス / 熱酸化膜 / 炭化ケイ素

Outline of Final Research Achievements

It is well know that the channel mobility of SiC MOSFETs is significantly affected by the interface formation processes. In this study, we found that a slight amount of additional oxidation in H2O (wet oxidation) of SiC after a conventional dry oxidation can improve the channel mobility on Si-face significantly, and that the required oxidation thickness to be grown in the wet oxidation is only less than 1nm. It was also clarified that the mobility was most efficiently improved for the case of wet oxidation at low temperature in the ambient with both H2O and O2. From the infrared analysis of the near-interface SiO2 structure in the region within 2 nm from SiC, we found that wet oxidation results in less strained structure than dry oxidation, which suggests the possibility that such structural relaxation would reduce the defect state density in oxide film.

Free Research Field

電子デバイス材料工学