Annealing of Proton and Alpha Particle Damage in Au-W/beta-Ga2O3 Rectifiers

Abstract

Vertical geometry Ga2O3 rectifiers were irradiated with 18 MeV alpha particles to fluences of 1-3 x 10(13) cm(-2) or 10 MeV protons to fluences of 1-3 x 10(14) cm(-2) and then annealed to establish the thermal stability of the radiation damage. The rectifiers employed Au/W rectifying contacts to achieve the requisite thermal stability to allow for annealing studies. The carrier removal rates were similar to 900 cm(-1) for the a-particles and similar to 200 for the protons. Annealing at 500 degrees C was found to restore the carrier concentration in the alpha-particle irradiated devices, while 450 degrees C annealing brought substantial recovery of the proton irradiated devices. This is a similar temperature range as established for annealing of plasma-induced damage in Ga2O3, suggesting a common origin of point defects, predominantly Ga vacancies and their complexes. The reverse breakdown voltages and diode on/off ratios are also significantly recovered by annealing after irradiation. (c) 2019 The Electrochemical Society.