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

Schottky diodes were formed on bulk or epitaxial β-Ga 2 O 3 using Ni/Au or Pt/Au and the electrical characteristics measured as a function of temperature in the range 25–200°C. The barrier heights were 1.07 eV (Ni/Au) and 1.04 eV (Pt/Au) at 25°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 (V B ), β, was −4 mV/K for Ni/Au and −0.1 mV/K for Pt/Au. The figure-of-merit (V B 2 /R ON ) was above 3 MW.cm −2 at 25°C for Ni/Au diodes and was still ∼1 MW.cm −2 at 200°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°C for both epi and bulk diodes. The results show the already high quality of bulk and epitaxial β-Ga 2 O 3 and the potential of this material for high temperature power electronics.