Correlation between leakage current and ion-irradiation induced defects in 4H-SiC Schottky diodes

The defects formation in ion-irradiated 4H-SiC was investigated and correlated with the electrical properties of Schottky diodes. The diodes were irradiated with 1 MeV Si+-ions, at fluences ranging between 1 x 10(9) cm(-2) and 1.8 x 10(13) cm(-2). After irradiation, the current-voltage characteristics of the diodes showed an increase of the leakage current with increasing ion fluence. The reverse I-V characteristics of the irradiated diodes monitored as a function of the temperature showed an Arrhenius dependence of the leakage, with an activation energy of 0.64 eV. Deep level transient spectroscopy (DLTS) allowed to demonstrate that the Z(1)/Z(2) center of 4H-SiC is the dominant defect in the increase of the leakage current in the irradiated material.