| Paper Abstract and Keywords |
| Presentation |
2012-06-27 11:30
[Invited Talk]
Gate Stack Technologies for Silicon Carbide Power MOS Devices
Takuji Hosoi, Takashi Kirino, Yusuke Uenishi, Daisuke Ikeguchi, Atthawut Chanthaphan (Osaka Univ.), Akitaka Yoshigoe, Yuden Teraoka (JAEA), Shuhei Mitani, Yuki Nakano, Takashi Nakamura (ROHM), Takayoshi Shimura, Heiji Watanabe (Osaka Univ.) |
| Abstract |
(in Japanese) |
(See Japanese page) |
| (in English) |
Silicon carbide (SiC) is a promising material for high-power electronic devices. Although SiO$_2$ dielectric film can be grown on SiC by conventional thermal oxidation, low channel mobility and poor gate oxide reliability are the critical issues for SiC power metal-oxide-semiconductor field-effect transistors (MOSFETs). In this work, we investigated the fundamental aspects of thermally grown SiO$_2$/4H-SiC structures such as an energy band alignment and flatband voltage (VFB) instability. Both electrical characterization and x-ray photoelectron spectroscopy (XPS) study revealed that a conduction band offset ($\Delta$E$_c$) between SiO$_2$ and SiC is extrinsically increased by large amount of negative interface charges. High-temperature hydrogen annealing could effectively passivate interface defects, but at the same time resulted in the reduced $\Delta$E$_c$ at SiO$_2$/SiC interfaces. We also found that intrinsic positive mobile ions exist in as-oxidized SiO$_2$/SiC structures. Post-oxidation annealing in Ar ambient mostly eliminates the mobile ions, but they are generated again by subsequent high-temperature hydrogen annealing despite the improved interface quality. These features were not observed for thermally-grown SiO$_2$/Si structures, and thus considered to be inherent to thermally grown SiO$_2$/SiC structures. |
| Keyword |
(in Japanese) |
(See Japanese page) |
| (in English) |
SiC / thermal oxide / MOS devices / interface defect / mobile ion / / / |
| Reference Info. |
IEICE Tech. Rep. |
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