Body-bias effect in a GaN Schottky barrier MOSFET fabricated on a silicon (111) substrate with an ITO Source/Drain

We fabricated a GaN Schottky barrier metal-oxide-semiconductor field-effect transistor (SBMOSFET) by using indium tin oxide (ITO) films as the source/drain and the gate electrodes, and we checked for the body bias effect after forming an Ohmic contact to the substrate. The body bias results exhibit an abnormal effect; i.e., the threshold voltage was decreased by a reverse body bias. In order to find the mechanism for that, we characterized the UV photo response of no-gated MOSFET used as a metal-semiconductor-metal (MSM) diode with and without annealing for the passivation oxide between the source and the drain regions. The leakage current of the back-to-back Schottky diode was significantly improved after passivation annealing, but the UV/visible rejection characteristics were worse.