Energy-Dependent Impact of Proton Irradiation on 4H-SiC Schottky Diodes

Abstract

In this work, the impact of 200 MeV proton irradiation at a fluence of 6 × 1012 cm−2 on the forward characteristics and the breakdown behaviour of nickel (Ni) and titanium (Ti) Schottky barrier diodes is explored. An improvement in the ideality factor, reduction in the threshold voltage, and an increase in the breakdown voltage is observed post irradiation. Point defects induced by the irradiation are likely responsible for the observed effects. Deep Level transient Spectroscopy (DLTS) measurements were performed on the irradiated Schottky diodes to analyse the defects created during the irradiation and gauge their potential role in changing the diode behavior. The defects induced by the high-energy protons were compared to those formed by low-energy proton irradiation at 1.8 MeV to a fluence of 1 × 1012 cm−2. Finally, consecutive DLTS measurements were performed after a series of reverse bias anneals at low temperatures from 350-700 K to explore the annealing behaviour of the defects induced by the proton irradiations.