High energy electron radiation effect on Ni and Ti/4H-SiC Schottky barrier diodes at room temperature

This paper reports that Ni and Ti/4H-SiC Schottky barrier diodes (SBDs) were fabricated and irradiated with 1 MeV electrons up to a dose of 3.43 × 1014 e/cm2. After radiation, the Schottky barrier height B of the Ni/4H-SiC SBD increased from 1.20 eV to 1.21 eV, but decreased from 0.95 eV to 0.94 eV for the Ti/4H-SiC SBD. The degradation of B could be explained by interface states of changed Schottky contacts. The on-state resistance RS of both diodes increased with the dose, which can be ascribed to the radiation defects. The reverse current of the Ni/4H-SiC SBD slightly increased, but for the Ti/4H-SiC SBD it basically remained the same. At room temperature, B of the diodes recovered completely after one week, and the RS partly recovered. © 2009 Chin. Phys. Soc. and IOP Publishing Ltd.