Enhanced β-Ga2O3 Schottky diode interface characteristics via low-temperature supercritical fluid technology

Abstract

This study presents a comprehensive investigation into the impact of supercritical fluid (SCF) N2O treatment on β-Ga2O3 Schottky barrier diodes (SBDs). Capacitance-voltage (C-V) analysis indicates a marginal reduction in the carrier concentration within the β-Ga2O3 drift layer post-SCF treatment. Remarkably, the treated SBDs exhibit substantial electrical enhancement: breakdown voltage surges from 355 to 551 V, reverse current density plunges by approximately two orders of magnitude, and Baliga’s figure of merit improves by 92.8%. Temperature-dependent forward current-voltage measurements further demonstrate superior high-temperature operational stability in SCF-processed devices. Crucially, frequency-dependent conductance measurements reveal a significant decrease in interface state density, from 2.62 × 1012–1.14 × 1013 cm−2 eV−1 to 8.5 × 1011–3.30 × 1012 cm−2 eV−1, alongside reduced trap activation energy (from 0.211–0.220 to 0.209–0.220 eV). These findings establish SCF treatment as a potent technique for interfacial engineering and performance optimization in β-Ga2O3 SBDs.