High-Temperature β-Ga2O3 Schottky Diodes and UVC Photodetectors Using RuOx Contacts

High-temperature beta-Ga2O3 Schottky diodes with very low leakage currents, capable of sensitive UVC detection at 350 degrees C, were fabricated on ((2) over bar 01) beta-Ga2O3 single crystal substrates using intentionally-oxidized ruthenium (RuOx) Schottky contacts (SCs), with x =similar to 2.1. These RuOx: beta-Ga2O3 SCs were characterized by rectification ratios of more than 10(10) at +/- 3 V and very low reverse leakage current densities of less than 1 nAcm(-2) (similar to 1 pA) at -3.0 V, that were unchanged from 24 to 350 degrees C. These very low high-temperature leakage currents were due to their extremely high Schottky barriers of 2.2 eV at 350 degrees C, that were stable against repeated operation at this temperature. Although not optimized for photodetection, these SCs could detect UVC (lambda = 248 nm) radiation at a temperature of 350 degrees C with a UVC/dark current ratio of similar to 10(3). The very high and thermally stable rectifying barriers of these RuOx: beta-Ga2O3 SCs makes them strong candidates for use in high temperature beta-Ga2O3 rectifying diodes and UVC photodetectors.