Determination of the leakage current transport mechanisms in quasi-vertical GaN–on–Si Schottky barrier diodes (SBDs) at low and high reverse biases and varied temperatures

Abstract

Temperature-dependent current–voltage characteristics was measured to investigate leakage conduction mechanisms in GaN-on-Si quasi-vertical Schottky barrier diode. At low reverse bias, thermionic emission is dominated. At voltage range from −1 to −20 V, variable range hopping (VRH) is main leakage current mechanism at low temperatures (298–373 K), while at high temperatures (498–573 K), electrons gain enough energy and emit into the trapped states, Frenkel–Poole emission becomes dominant. At a relatively high voltage range, the increased electric field promotes the electron hopping along the threading dislocation in the bulk GaN layers, and VRH becomes the main current mechanism at whole measured temperature range (298–573 K).