Impact of interface defect passivation on conduction band offset at SiO/4H-SiC interface

SiO/4H-SiC界面の伝導帯バンドオフセットに対する界面欠陥終端の効果

細井 卓治*; 桐野 嵩史*; Chanthaphan, A.*; 上西 悠介*; 池口 大輔*; 吉越 章隆 ; 寺岡 有殿; 箕谷 周平*; 中野 佑紀*; 中村 孝*; 志村 考功*; 渡部 平司*

Hosoi, Takuji*; Kirino, Takashi*; Chanthaphan, A.*; Uenishi, Yusuke*; Ikeguchi, Daisuke*; Yoshigoe, Akitaka; Teraoka, Yuden; Mitani, Shuhei*; Nakano, Yuki*; Nakamura, Takashi*; Shimura, Takayoshi*; Watanabe, Heiji*

The energy band alignments of thermally grown SiO/SiC structures were investigated by means of synchrotron radiation photoelectron spectroscopy (SR-PES) and electrical characterization of SiC-MOS capacitors. In order to determine the energy band alignments of SiO/SiC, band gaps of the thermal oxides and valence band offsets at the interface were examined by SR-PES. SiC-MOS capacitors with Al electrodes were also fabricated to evaluate interface state density and conduction band offset. Experimental results indicate that hydrogen atoms are effective to terminate carbon-related defects. It can be concluded that interface quality degradation due to hydrogen desorption by vacuum annealing causes reduction of conduction band offset for thermally grown SiO/SiC structure.