High-Temperature $\beta$ -Ga2O3 Schottky Diodes and UVC Photodetectors Using RuOx Contacts

High-temperature β-Ga
₂
O
₃
Schottky diodes with very low leakage currents, capable of sensitive UVC detection at 350°C, were fabricated on (2̅01) β-Ga
₂
O
₃
single crystal substrates using intentionally-oxidized ruthenium (RuOx) Schottky contacts (SCs), with x =~ 2.1. These RuO
_x
:β-Ga
₂
O
₃
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
(~1 pA) at -3.0 V, that were unchanged from 24 to 350 °C. These very low high-temperature leakage currents were due to their extremely high Schottky barriers of 2.2 eV at 350°C, that were stable against repeated operation at this temperature. Although not optimized for photodetection,these SCs could detect UVC (λ = 248 nm) radiation at a temperature of 350 °C with a UVC/dark current ratio of ~103. The very high and thermally stable rectifying barriers of these RuO
_x
:β-Ga
₂
O
₃
SCs makes them strong candidates for use in high temperature β-Ga
₂
O
₃
rectifying diodes and UVC photodetectors.