High energy electron radiation effect on Ni and Ti/4H-SiCSchottky barrier diode 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 $3.43\times10^{14}$~e/cm$^{2}$. After radiation, the Schottky barrier height $\phi _{\rm 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 $\phi _{\rm B} $ could be explained by interface states of changed Schottky contacts. The on-state resistance $R_{\rm S}$ 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, $\phi _{\rm B} $ of the diodes recovered completely after one week, and the $R_{\rm S}$ partly recovered.