Modification of SiO_2/4H-SiC Interface Properties by High-Pressure H_2O Vapor Annealing

摘要

We performed high-pressure H_2O vapor annealing on 4H-SiC n-MOS capacitors to control SiO_2/4H-SiC interface properties. High-pressure H_2O annealing was performed at 270～ 420°C at a pressure of 1.31～1.67MPa. Effective negative fixed oxide charge decreased with increasing anneal temperature in the case annealed with Al gate electrodes. However, it increased with increasing anneal temperature in the case annealed without Al gate electrodes. The effect of annealing was much larger on the C-face than that of Si-face. Interface state densities near the conduction band edge was decreased at 420°C under 1.67MPa compared to other samples, especially on the C-face n-MOS capacitors.