Influence of swift heavy ion irradiation on electrical characteristics of β-Ga2O3 Schottky barrier diode

Abstract

The radiation effect of swift heavy ions (16 MeV 181Ta) on the Au/Ni/β-Ga2O3 vertical Schottky barrier diodes (SBDs) were investigated at the fluence of 1 × 108, 3 × 108 and 3 × 109 cm−2. The SBDs were characterized by current density–voltage (J–V) and capacitance–voltage (C–V) measurements. It was found that Schottky barrier height φ decreased from 1.11 eV to 0.94 eV, the ideality factor n increased from 1.01 to 1.29, turn-on voltage V on increased from 0.52 V to 0.80 V after radiation of 3 × 109 cm−2. The reverse breakdown voltage was decreased from −405 V to −375 V, −350 V and −255 V after radiation of 1 × 108, 3 × 108 and 3 × 109 cm−2, respectively. In addition, the carrier concentration calculated from the capacitance–voltage curves was decreased significantly. Based on the G/ω–ω measurement results, the trap density at the Ni/β-Ga2O3 interface was extracted to be 2.89 × 1015–2.49 × 1016 cm−2 eV−1 and 2.18 × 1015–4.98 × 1016 cm−2 eV−1 with the energy level of 0.85–0.87 eV below the conduction band edge.