Defects and electrical behaviour in 1 MeV ion irradiated 4H-SiC Schottky diodes

In this paper, the formation and evolution of defects induced by ion irradiation with 1 MeV Si+ ionsin Ni2Si/4H–SiC Schottky diodes were studied and correlated with the electrical properties of thecontacts. The current-voltage characteristics of the contacts monitored before and after irradiationshowed an increase of the Schottky barrier height, of the series resistance, and of the leakage currentwith increasing irradiation fluence. The changes in the barrier height and in the series resistancevalues could be attributed to the dopant deactivation in the near-interface region, while the increaseof the leakage current was associated with the formation of irradiation-induced defects. Thesedefects showed an evolution with increasing irradiation fluence. Moreover, a combination ofdeep-level transient spectroscopy and current-voltage measurements of the diodes allowed us todemonstrate that the Z1 /Z2 center of 4H–SiC has the major influence on the increase of the diodesleakage current in the irradiated material