Improved nickel silicide ohmic contacts to n-type 4H and 6H-SiC using nichrome

Results are reported for ohmic contacts formed on n-type 4H and 6H-SiC using nichrome (80/20 weight percent Ni/Cr). In comparison to contacts formed on 6H-SiC using pure Ni, the electrical characteristics of these NiCr contacts are similar (similar to 1E-5 Omega-cm(2) for moderately doped material), and composite Au/NiCr contacts exhibit good stability during long-term anneals (similar to 2500 hr) at 300 C without the requirement of a diffusion barrier layer between the ohmic contact layer and the Au cap layer. The use of NiCr also results in success rates near 100% for direct wire bonding to the Au cap layers.