Comparison of stability of WSi_(X)/SiC and Ni/SiC Schottky rectifiers to high dose gamma-ray irradiation

摘要

SiC Schottky rectifiers with moderate breakdown voltages of ～450 V and with either WSi_(X) or Ni rectifying contacts were irradiated with Co-60 γ-rays to doses up to ～315 Mrad. The Ni/SiC rectifiers show severe reaction of the contact after irradiation at the highest dose, badly degrading the forward current characteristics and increasing the on-state resistance by up to a factor of 6 after irradiation. By sharp contrast, the WSi_(X)/SiC devices show little deterioration of the contact with the same conditions and changes in on-state resistance of <20%. The WSi_(X) contacts appear promising for applications requiring improved contact stability.