2017年第78回応用物理学会秋季学術講演会

講演情報

一般セッション(口頭講演)

15 結晶工学 » 15.6 IV族系化合物(SiC)

[5a-A203-1~10] 15.6 IV族系化合物(SiC)

2017年9月5日(火) 09:00 〜 11:45 A203 (203)

細井 卓治(阪大)

10:00 〜 10:15

[5a-A203-5] Verification of density distribution of near-interface traps in 4H-SiC MOS capacitors with different oxide thicknesses

〇(D)Xufang Zhang1、Dai Okamoto1、Tetsuo Hatakeyama2、Mitsuru Sometani2、Shinsuke Harada2、Noriyuki Iwamuro1、Hiroshi Yano1 (1.Tsukuba Univ.、2.AIST)

キーワード:4H-SiC MOS capacitors, Near-interface traps, density distribution

Near-interface traps (NITs) are one of the most harmful oxide defects locating near the interface of SiO2/4H-SiC, which leads to the poor properties of 4H-SiC MOSFETs. Recently, we have developed a modified distributed circuit model to characterize the NITs. In the proposed model, we assumed an exponentially decaying distribution of NITs for 4H-SiC MOS capacitors with oxide thickness of around 50 nm to explain both the Cf and Gf characteristics in strong accumulation conditions. However, the exponential distribution assumption has not been fully validated. To assess the validity of the exponential assumption of NITs, it would be effective to test the distributed circuit model for different oxide thicknesses formed by different oxidation times. On the other hand, Watanabe et al. reported that the Dit depends on oxidation time, and the Dit increases with increasing the oxide thickness. Here, we verified the exponential approximation of NIT distribution by using the MOS capacitors formed by different oxidation times and also investigated the impact of oxidation time on the NIT density distribution in 4H-SiC MOS capacitors with the proposed model.