1.5 MeV electron irradiation damage in beta-Ga2O3 vertical rectifiers

Abstract

Vertical rectifiers fabricated on epi Ga2O3 on bulk beta-Ga2O3 were subject to 1.5MeV electron irradiation at fluences from 1.79 x 10(15) to 1.43 x 10(16) cm(-2) at a fixed beam current of 10(-3) A. The electron irradiation caused a reduction in carrier concentration in the epi Ga2O3, with a carrier removal rate of 4.9 cm(-1). The 2 kT region of the forward current-voltage characteristics increased due to electron-induced damage, with an increase in diode ideality factor of similar to 8% at the highest fluence and a more than 2 order of magnitude increase in on-state resistance. There was a significant reduction in reverse bias current, which scaled with electron fluence. The on/off ratio at -10V reverse bias voltage was severely degraded by electron irradiation, decreasing from similar to 10(7) in the reference diodes to similar to 2 x 10(4) for the 1.43 x 10(16) cm(-2) fluence. The reverse recovery characteristics showed little change even at the highest fluence, with values in the range of 21-25 ns for all rectifiers. (C) 2017 American Vacuum Society.