Effects of combined NO and forming gas annealing on interfacial properties and oxide reliability of 4H-SiC MOS structures

• DOI: 10.1016/j.microrel.2015.11.022
• Publication Date: 2015-12-05T01:15:21Z
• Authors: Zhaoyang Peng; Yiyu Wang; Huajun Shen; Chengzhan Li; Jia Wu; Yun Bai; Kean Liu; Xinyu Liu
• Keywords: 0103 physical sciences; 01 natural sciences

Abstract The effects of NO and forming gas post oxidation annealing treatments on the interfacial properties and reliability of thermal oxides grown on n-type 4H-SiC (0001) Si face have been investigated in this study. The results show that forming gas annealing (FGA) treatment has limited effect on interface trap density ( D it ) while it results in an improvement of the insulating properties of thermal oxide with uniform high FN barrier height (2.56 eV), high field-to-breakdown (10.71 MV/cm) and charge-to-breakdown (0.078 C/cm 2 ). On the other hand, NO annealing causes a drastic reduction in D it in the entire energy level, but in the case of reliability, it is not so effective as FGA, with lower barrier height (2.52 eV), field-to-breakdown (10.08 MV/cm), charge-to-breakdown (0.025 C/cm 2 ) and worse uniformity of oxide. The combined NO&FGA treatment was also studied. It leads to a significant reduction in interface trap density further, especially in deep energy level ( E C -E T ≥ 0.4 eV). As for reliability, it brings about uniform barrier height (2.69 eV), field-to-breakdown (10.15 MV/cm) and charge-to-breakdown (0.024 C/cm 2 ). Taking interfacial properties and reliability into account, combined NO&FGA treatment is a promising POA technique for fabrication of high-quality SiC MOS devices.