Leakage current by Poole–Frenkel emission in Pt Schottky contacts on (201) ^¯ β-Ga₂O₃ grown by edge-defined film-fed growth

We report an investigation of the leakage current in Pt/β-Ga₂O₃ Schottky contacts on an (201) ^¯ substrate using a temperature-dependent current–voltage (I-V-T) measurement in a temperature range of 300 K to 425 K. It was revealed that the main process of the reverse leakage current flow is the emission of electrons through trap states located near the metal-semiconductor interface, governed by the Poole-Frenkel emission (PFE). Based on an etch pits analysis, the density of the defects at the surface of the (201) ^¯ β-Ga₂O₃ substrates was estimated to be ∼2 × 10⁵ cm⁻². The trap states associated with these high-density defects, which could be the main culprit for the reverse leakage current in the Pt/β-Ga₂O₃ Schottky contacts, were identified at ∼ 0.7 eV below the conduction band.