Determination of Band Structure at GaAs/4H-SiC Heterojunctions

Abstract

The effects of thermal annealing process on the interface in p+-GaAs/n-SiC heterojunctions fabricated by using surface-activated bonding (SAB) were investigated. It was found by measuring their current-voltage (I-V) characteristics that the reverse-bias current and the ideality factor were extracted to be 7.57 ´ 10-7 A/cm2 and 1.33, respectively, for the junctions annealed at 400 °C. The flat-band voltage obtained from capacitance-voltage (C-V) measurements was found to be 1.29 eV, which is almost consistent with the turn-on voltage extracted from I-V characteristics. These results suggest that the SAB-based GaAs/SiC heterojunctions are applicable for fabricating high-frequency power devices.