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

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 degrees C for 10 min 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. (C) 2013 Elsevier B.V. All rights reserved.