Presentation Information
[11p-A21-3]Deterioration of β-Ga2O3 MOS Interface Characteristics by TMAH Surface-Smoothing Etching and Its Suppression by Lowering Etching Temperature and O3 Oxidation
〇Hayama Imaida1, Atsushi Tamura1, Koji Kita1 (1.GSFS, The Univ. of Tokyo)
Keywords:
Ga2O3,TMAH,O3
We have previously investigated the effects of O3 surface oxidation and TMAH etching as surface treatments on β-Ga2O3 MOS interface characteristics. While O3 oxidation improved the MOS characteristics, TMAH etching at 60 °C degraded them. In this study, we reexamined the conditions of TMAH etching and investigated their effects on surface morphology and MOS characteristics. The results showed that TMAH etching formed a step-and-terrace structure, and in particular, prolonged etching at room temperature yielded the smoothest surface with reduced roughness. In addition, no deterioration in MOS characteristics was observed by room-temperature etching. Furthermore, subsequent O3 treatment led to both a smooth surface and a good MOS interface with a low interface state density.