Impact of post-deposition annealing on SiO2/SiC interfaces formed by plasma nitridation of the SiC surface and SiO2 deposition

Abstract

We examined the impact of post-deposition annealing (PDA) on SiO _2 /SiC structures formed by plasma nitridation of the SiC surface followed by sputter deposition of SiO _2 . The interface state density near the conduction band edge of SiC was reduced from about 2 × 10 ^12 to 1 × 10 ^11 eV ^−1 cm ^−2 as the CO _2 -PDA temperature increased from 1050 °C to 1250 °C. In addition, the sample treated by CO _2 -PDA exhibited substantially higher immunity against positive gate bias stress than the standard NO nitridation. Our findings indicate that defect passivation by CO _2 -PDA plays a crucial role in improving the performance and reliability of SiC MOS devices formed by sputter-SiO _2 deposition.

Keywords

• silicon carbide
• MOS interface
• interface state density