Metal-oxide-semiconductor devices using Ga2O3 dielectrics on n-type GaN

Using a photoelectrochemical method involving a He-Cd laser, Ga2O3 oxide layers were directly grown on n-type GaN. We demonstrated the performance of the resultant metal-oxide-semiconductor devices based on the grown Ga2O3 layer. An extremely low reverse leakage current of 200 pA was achieved when devices operated at -20 V. Furthermore, high forward and reverse breakdown electric fields of 2.80 MV/cm and 5.70 MV/cm, respectively, were obtained. Using a photoassisted current-voltage method, a low interface state density of 2.53x10(11) cm(-2) eV(-1) was estimated. The varactor devices permit formation of inversion layers, so that they may be applied for the fabrication of metal-oxide-semiconductor field-effect transistors. (C) 2003 American Institute of Physics.