Capacitance-voltage characterization of surface-treated Al2O3/GaN metal-oxide-semiconductor structures.

Display Omitted We show the effect of surface treatment between the Al2O3 and the recess-etched GaN.We have investigated the effect of TMAH surface treatment.The C-V characteristics were improved with the surface treatment.We result low effective oxide charge and interface trap density.We result less charge trapping in the gate dielectric. The effect of surface treatment on the interfacial properties between the Al2O3 gate dielectric and the recess-etched GaN surface of the AlGaN/GaN-based MOSFET has been characterized by capacitance-voltage (C-V) measurements. The recessed GaN surface was treated in the tetramethylammonium hydroxide (TMAH) solution at 85?C for 10min to smoothen the surface and remove the plasma damage. The surface treatment decreases the interface trap density by removing surface traps related to the native surface oxide such as GaxOy, which results in much improved C-V characteristics.