Synthesis and characterization of Ti-Si-C compounds for electrical contact applications

We present a growth study of Ti-Si-C thin films on Cu and Al substrates for contact resistance studies. The films were grown by magnetron sputtering from Ti/sub 3/SiC/sub 2/ compound targets at temperatures from 100 /spl deg/C to 300 /spl deg/C. The films consist of TiC/sub x/ nanocrystallites embedded in an amorphous SiC matrix. Mechanically, the Ti-Si-C films exhibit a nanoindentation hardness of 20 GPa and an elastic modulus of 290 GPa, reflecting a carbidic nature but with a remarkable ductile behavior. In electrical contact studies, the contact resistance of the Ti-Si-C films, deposited on Ni-plated Al washers at 300 /spl deg/C, against Ag was comparable to that of Ag against Ag at high contact forces (6 /spl mu//spl Omega/, and 3.2 /spl mu//spl Omega/, respectively, at 800 N). At lower forces the difference is significant due to the formation of surface oxides. In a crossed cylinder setup, the contact resistance of Ti-Si-C films deposited on Ni-plated Cu cylinders is typically a factor 5 higher than that of Ag against Ag. Encouragingly, Ti-Si-C films deposited at 100 /spl deg/C exhibited contact resistances less than double of that of films deposited at 300 /spl deg/C. We conclude that, while significant work remains on process optimization and analysis, Ti-Si-C has high potential in general electrical contact applications.