Copper ohmic contacts to n-type SiC formed with pulsed excimer laser irradiation

Abstract

Copper-based ohmic contacts to n-type 6H-SiC have been investigated. In this study, ohmic contacts have been fabricated with pulsed excimer laser irradiation to Cu-deposited substrates at room temperature. It is shown that current-voltage characteristics depend on the laser energy density. Contacts formed by the laser irradiation at the energy density above 1.2 J/cm 2 have shown the ohmic behavior. Cu atoms have slightly diffused into SiC by the laser irradiation at 1.4 J/cm 2 . As a result, a thin ohmic contact layer has been obtained by the laser processing. AES and XRD study have revealed that a Cu-SiC alloy containing Cu silicide (Cu 3 Si) is formed by the laser irradiation.