High-Temperature $\beta$ -Ga2O3Schottky Diodes and UVC Photodetectors Using RuOxContacts

Caixia Hou,Roger J Reeves,Martin W Allen,Rodrigo M Gazoni

doi:10.1109/led.2019.2937494

Abstract

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.

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