Mechanism of Reduction of Interface-State Density in the SiC/Metal Contact by Hydrogenation

The mechanism of lowering the density of interface states due to hydrogenating SiC surface was studied. The treatment of hydrogenation SiC surface by slowly oxidizing,etching by dilute HF and then immersing in boiling water was utilized to lower the density of surface states. The method was applied to treat the surface during fabricating SiC device. SiC Schottky diodes with ideality factor of 1.2~1.25 and ohmic contacts with specific resistance of (5~7)×10-3Ω· cm2 were obtained below 100℃. Its advantages lay in avoiding the high-temperature annealing at 800~1 200℃ for conventional Ohmic contacts, decreasing technical difficulty, and improving the electric performances of SiC Schottky junction.