[21a-M206-1~13] 13.7 Compound and power devices, process technology and characterization

[21a-M206-7] First-principles study on NO-annealed SiC/SiO₂ interface atomic structure

〇Mizuho Ohmoto¹, Naoki Komatsu¹, Mitsuharu Uemoto¹, Tomoya Ono¹ (1.Kobe Univ.)

Keywords:SiC, NO-annealing, interface atomic structure

Due to the large number of defects at the SiC MOS interface, the carrier mobility is significantly lower than that in the bulk, resulting in insufficient performance. NO annealing is used to reduce the defect density and to increase channel mobility as a post-oxidation process. However, the interface atomic structure after NO annealing is unclear. In this study, using the experimental results that N atoms accumulate on the SiC substrate surface, the most stable face (a, m, or Si face) for NO annealing and the interface atomic structure after NO annealing are investigated by the first-principles calculation based on density functional theory. It is found that the reaction energy for NO annealing at the a-face is the lowest and the nitride layer is formed immediately below the SiO ₂ layer of the interface.