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

Degradation of ohmic contacts on β ‐Ga 2 O 3 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 ‐Ga 2 O 3 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 ‐Ga 2 O 3 channel. Even with the extended Schottky metal region, the β ‐Ga 2 O 3 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.