Inversion behavior in Sc2O3/GaN gated diodes

The capacitance-voltage (C-V) characteristics of Sc2O3/p-GaN gate-controlled diodes show unusual hook shapes due to the charging of surface states. From the drain-voltage dependence of the C-V curves, the total surface state density was estimated to be similar to8.2x10(12) cm(-2) for diodes undergoing an implant activation anneal at 950 degreesC. The accumulation capacitance showed a significant dependence on measurement frequency and is suggested to result from the presence of an interfacial dielectric between the Sc2O3 and GaN. The Si-implanted n(+) regions in the gated diode structure are effective in providing a source of inversion charge. (C) 2002 American Institute of Physics.