Effect of 6.5 MeV proton irradiation on the performance of 4H-SiC Schottky barrier photodiode

Irradiation introduces some electronic energy levels within the forbidden energy gap of semiconductors. In this paper, the effects of energy levels caused by proton irradiation with different fluences on the device performance of a 4H-SiC Schottky barrier ultraviolet photodiode is investigated. The modeling for resulting energy levels is carried out by a 2D device simulator. Results for electrical and optical properties of the irradiated photodiode compared to the unirradiated one is obtained by simulation. In this paper, it is demonstrated that series resistance changes from 28.8 mΩ for the unirradiated photodiode to 47.8 mΩ for the irradiated photodiode at highest fluence exposure. A significant reduction in quantum efficiency is observed for the photodiode at wavelengths longer than about 270 nm as the irradiation fluence increases.