Effect of metal electrode on characteristics of gamma-irradiated silicon carbide detector

Abstract

Silicon carbide (SiC) is a highly promising semiconductor neutron-detector material for harsh environments such as nuclear reactor cores and spent-fuel storage pools. In the present study, three 4H-SiC p-i-n diode detectors were fabricated as variations of those metal-electrode structures. The I-V characteristics and alpha-particle responses of the detectors were measured before and after gamma-ray exposure. The detector with a Ti/Au electrode showed the lowest change of leakage current after irradiation; none of the detectors showed any change in the charge-collection efficiency when a sufficient electric field was applied after gamma irradiation of up to 8.1 MGy.

SiC detectors: A review on the use of silicon carbide as radiation detection material

“…The detectors equipped with the Ti/Au electrode show the lowest increase in leakage current, from 0.18 to 0.31 μA at 100 V, while those equipped with the Ni/Au electrode show the highest increase, with a value of 0.24 μA, which is a factor 15 higher than the pre-irradiation value. The CCE measured with 238 Pu generated αs after 8.1 MGy irradiation still reached 100%, but for a reverse bias about four times higher (about 160 V) than that required before irradiation, regardless of the electrode type [153].…”

“…In Ref. [153], the role of the metal electrode on the radiation tolerance of gamma-irradiated SiC was investigated. With electrode structures of Cr/Au, Ni/Au, and Ti/Au (Cr, Ni, or Ti of 30 nm thickness deposited by sputtering, plus 200 μm Au deposited by the thermal evaporator), three detectors were used.…”