A Hybrid Schottky–Ohmic Drain Contact for Thermally Stressed Beta‐Gallium Oxide Field‐Effect Transistors

Abstract

Degradation of ohmic contacts on β‐Ga2O3 under thermal stress conditions is a severe issue that hinders its high‐temperature applicability. Herein, a hybrid Schottky–ohmic drain contact (HSD) is demonstrated in β‐Ga2O3 field‐effect transistors (FETs). It is compared with a conventional ohmic drain contact (OD) after extended thermal annealing. Pulsed drain bias measurement is conducted to investigate the trapping process at the interface of both drain contacts with the β‐Ga2O3 channel. Even with the extended Schottky metal region, the β‐Ga2O3 FET with the HSD contact exhibits similar contact and on‐resistance. Additionally, it shows field‐effect mobility higher than that of the OD contact device. Enhanced off‐state breakdown characteristics are achieved.