[16p-PA04-1~24] 13.7 Compound and power devices, process technology and characterization

[16p-PA04-3] Electron Spin Resonance spectroscopy (ESR/EDMR) study on interface defects at (11-20) face (a-face) 4H-SiC/SiO₂ interfaces

〇Ren Kondo¹, Mitsuru Sometani^2,3, Heiji Watanabe³, Takahide Umeda¹ (1.Univ. of Tsukuba, 2.AIST, 3.Osaka Univ.)

Keywords:4H-SiC(11-20), MOS interface states, Electron spin resonance spectroscopy

Using electron-spin-resonance (ESR) and electrically-detected-magnetic-resonance (EDMR) spectroscopy, we study MOS interface defects at 4H-SiC(11-20)/SiO₂ structures. We observed no interface ESR signals in free-standing epitaxially-grown 4H-SiC(11-20) substrates with dry oxidation, suggesting that interface defects have unoccupied or doubly-occupied electronic states. Using EDMR spectroscopy on 4H-SiC(11-20) MOSFETs, we observed an weak interface signal under negative gate bias, which arises from valence-band-side interface defects. This result suggests that the valence-band-side interface states are much less than those in Si-face 4H-SiC MOSFETs.