GaN Metal–Oxide–Semiconductor Field-Effect Transistor with Tetraethylorthosilicate SiO2 Gate Insulator on AlGaN/GaN Heterostructure

Abstract

GaN metal–oxide–semiconductor field-effect transistors (MOSFETs) with a tetraethylorthosilicate (TEOS) SiO2 insulator were developed and evaluated using an AlGaN/GaN HFET structure as the source and drain regions. Operation up to a gate voltage of 10 V was realized at a low gate leakage current. A new method of measuring the mobility of a MOSFET was developed to prevent the effect of hysteresis, in which a relay was used to switch between current measurement and capacitance measurement at the same gate voltage. The maximum field-effect mobility is approximately 45 cm2 V-1 s-1 at an interface state density of 1.02 ×1013 cm-2 eV-1.