ARXPS-ANALYSIS OF SPUTTERED TIC, SIC AND TI0.5SI0.5C LAYERS

TiC, SiC and Ti0.5Si0.5C 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 Ti0.5Si0.5C, 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 mOMEGA cm. The excess C segregates to the surface of TiC nanocrystallites showing an XPS C ls 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 Ti0.5Si0.5C layers allows the modelling of the TiC nanocrystallites embedded in interfacial carbon and defective SiC.