Temperature-Dependent Characteristics of Ni/Au and Pt/Au Schottky Diodes on β-Ga2O3

Schottky diodes were formed on bulk or epitaxial beta-Ga2O3 using Ni/Au or Pt/Au and the electrical characteristics measured as a function of temperature in the range 25-200 degrees C. The barrier heights were 1.07 eV (Ni/Au) and 1.04 eV (Pt/Au) at 25 degrees C. The barrier heights increased with temperature, while the on-state resistances (R-ON) decreased over the same range. The temperature coefficient of reverse breakdown voltage (VB), beta, was-4 mV/K for Ni/Au and -0.1 mV/K for Pt/Au. The figure-of-merit (VB2/RON) was above 3 MW. cm(-2) at 25 degrees C for Ni/Au diodes and was still similar to 1 MW. cm(-2) at 200 degrees C. The reverse recovery times were also measured as a function of temperature and were of the order of 21-28 ns over the range 25-150 degrees C for both epi and bulk diodes. The results show the already high quality of bulk and epitaxial -beta-Ga2O3 and the potential of this material for high temperature power electronics. (C) 2017 The Electrochemical Society. All rights reserved.