[16a-1A-1~11] 15.6 Group IV Compound Semiconductors (SiC)

▼ [16a-1A-8] Interface nitridation of thermally-grown SiO₂/4H-SiC by post-oxidation annealing in pure nitrogen gas

〇(P)Atthawut Chanthaphan¹, Yen Hung Cheng¹, Takuji Hosoi¹, Takayoshi Shimura¹, Heiji Watanabe¹ (1.Osaka Univ.)

Keywords:SiC-MOS,nitrogen,POA

We demonstrated an alternative approach to incorporate nitrogen atoms into the SiO₂/SiC interface by high-temperature POA in pure N₂ ambient. We affirmed that the fundamental requirements for achieving interface nitridation under pure N₂ ambient were a proper initial oxide thickness (less than 15 nm) and an adequate thermal budget (higher than 1350°C). The interface nitridation was possible to be enhanced by increasing the annealing temperature. The electrical properties of the SiC-MOS devices were examined and found to have advantages of N₂-POA that were comparable to the former reports on NO-POA. Although an amount of fast states were generated at the SiO₂/SiC interfaces, just as with the standard NO-POA, the proposed N₂-POA was found to be beneficial for incorporating a larger amount of nitrogen atoms and passivating dominant slow traps at the interface even under the harmless conditions.