Processing and characterization of co silicide ohmic contacts to 4H–SiC

Silicon carbide (SiC) is a promising material for power devices because of its wide bandgap and high thermal conductivity. However, carbon remaining in the metal–SiC interface (carbon cluster) adversely affects the ohmic contacts. As a result, the ohmic contact characteristic worsens and the on-state power loss of the device increases. In addition, the carbon cluster in the metal–SiC interface degrades the device’s high-temperature thermal stability. In this paper, Co/Si/Co/Si is used as an ohmic contact material to reduce the carbon cluster and improve the thermal stability. The specific contact resistivity was measured, and the effect of the Co:Si composition ratio and the annealing condition for the ohmic contact was analyzed. The thermal stability was investigated by measuring the specific contact resistivity through a thermal duration test. The measurement results were analyzed using the X-ray diffraction method.