Temperature-dependent current transport in quasi-vertical Pt/AlN/Al0.6Ga0.4N heterostructure Schottky barrier diodes with significant improved forward characteristic

Abstract

Abstract In this letter, quasi-vertical Schottky barrier diodes (SBDs) based on AlN/Al0.6Ga0.4N heterostructure are fabricated and temperature-dependent current transport is systematically investigated. Benefited from the AlN/Al0.6Ga0.4N heterostructure with high net doping concentration of ∼1 × 1018 cm−3 in Al0.6Ga0.4N, the device demonstrates lower ideality factor of 2.95, high on/off current ratio of ∼108, the on-current of above 40 A cm−2 which is two order magnitude higher than that of the state-of-the-art AlN SBDs. The barrier inhomogeneity is characterized by the model of Gaussian distribution, and the reverse current observed is identified to be traps-related leakage process such as Poole–Frenkel emission and trap assisted tunneling. This work reveals the heterostructure engineering is an alternative pathway to overcome the difficulty of AlN-based SBDs.