Leakage Current by Poole–Frenkel Emission in Pt Schottky Contacts on () β-Ga 2 O 3 Grown by Edge-Defined Film-Fed Growth

Abstract

© The Author(s) 2019. 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.