AlGaN/GaN high electron mobility transistors with nickel oxide based gates formed by high temperature oxidation

Abstract

We report on the design of gates of AlGaN/GaN high electron mobility transistors (HEMTs) to be predetermined for high temperature applications. In this design, nickel oxide (NiO) gate interfacial layer is formed by high temperature oxidation (T = 500–800 °C, for 1 min) of 15 nm thick Ni gate contact layer to provide a high temperature stable gate interface. AlGaN/GaN HEMTs with thermic NiO gate contact layer show excellent dc performance with higher peak transconductance, larger gate voltage swing, higher linearity, and thermal stability as compared to the reference device based on Ni gate contact layer.