Electrical and optical characterization of electron-irradiated 4H-SiC epitaxial layers annealed at low temperature

In this work, we report and discuss the results of minority carriers diffusion length measurements carried out in order to quantify the radiation damage induced by electron irradiation of X-rays detectors based on a metal–silicon carbide junction.The devices examined consisted of 4H-SiC n-type epitaxial layers on 4H-SiC nq-type substrate wafers, on which Schottky contacts were formed by gold deposition.The minority carriers diffusion length, extracted from the results of photocurrent measurements using a fitting procedure, was shown to exhibit a strong decrease with the radiation dose.