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 SiO2/SiC structures formed by plasma nitridation of the SiC surface followed by sputter deposition of SiO2. The interface state density near the conduction band edge of SiC was reduced from about 2×1012 to 1×1011 eV−1cm−2 as the CO2-PDA temperature increased from 1050 to 1250℃. In addition, the sample treated by CO2-PDA exhibited substantially higher immunity against positive gate bias stress than the standard NO nitridation. Our findings indicate that defect passivation by CO2-PDA plays a crucial role in improving the performance and reliability of SiC MOS devices formed by sputter-SiO2 deposition.