[20a-141-1~13] 15.6 Group IV Compound Semiconductors (SiC)

▲ [20a-141-4] Effects of wet-POA with various conditions on 4H-SiC m-face MOS interface properties

〇(M1)Qiao Chu¹, Kensaku Yamamoto², Sumera Shimizu², Koji Kita¹ (1.The Univ. of Tokyo, 2.DENSO CORP.)

Keywords:Silicon Carbide, MOS, wet oxidation

Wet oxidation of SiC often results in significantly different MOS interface properties from dry oxidation. For both Si-face and m-face, we have reported the reduction of MOS interface state density (D_it) by the combination of dry oxidation and wet-POA, but the impact of the selection of wet-POA conditions has not been clarified. In this research, we systematically investigated the effects of wet-POA with various conditions on m-face, focusing on D_it and bias stress instability.
In a conclusion, significant reduction of D_it was demonstrated on 4H-SiC m-face, by dry oxidation followed by wet-POA. The reduction of D_it was most pronounced for the wet-POA with a small O₂ content in the ambience, whereas the V_fb stability under a positive gate bias was improved by suppressing O₂ introduction to the wet-POA ambience.