ARXPS-analysis of sputtered TiC, SiC and Ti_0.5Si_0.5C layers

Summary

TiC, SiC and Ti_0.5Si_0.5C layers have been deposited by magnetron sputtering in Argon at bias voltages between 0 and 1500 V. AES and ARXPS analyses show that TiC and Ti_0.5Si_0.5C, at bias voltages below 1000 V, are C-rich (+20%) and contain TiC crystallites of diameter below about 10 nm and have a metal-like resistance of about mΩcm. The excess C segregates to the surface of TiC nanocrystallites showing an XPS C 1s level shift similar to Li-graphite or doped fullerenes. The doped carbon (‘carbidic’) interface layer, higher deposition rate and better mechanical strength seem to be interrelated. Magnetron sputtered SiC is X-ray amorphous and insulating, grows more slowly, has reduced mechanical strength and does not contain excess C. The ARXPS analysis of Ti_0.5Si_0.5C layers allows the modelling of the TiC nanocrystallites embedded in interfacial carbon and defective SiC.