Preparation of TiC films by alternate deposition of Ti and C layers using a dual magnetron sputtering source

Titanium carbide (TiC) films have been prepared by alternately depositing t hin Ti and C layers on aluminosilicate glass substrate by magnetron sputter ing. The apparatus used in the experiment was a dual-cathode-sputtering mac hine with a carousel type substrate holder. By rotating the substrate holde r at a rotation speed of 30 rev/min, a thin Ti layer of 0-0.15 nm and a thi n C layer of 0-0.072 nm depending on the cathode current were alternately d eposited on the substrate. The Ti/C compositional ratios of films were cont rolled by varying the flux ratio (layer thickness ratio) of the Ti and C so urces. This allowed films of Ti, TiC, and C to be prepared. The composition , structure, and hardness of the deposited films were estimated as a functi on of the source C/Ti flux ratio. The results of X-ray photoelectron spectr oscopy showed that the film composition varied continuously from Ti:C = 1:0 to 0:1, and that some oxygen was incorporated as an impurity for low C/Ti ratios. The X-ray diffraction measurement results showed that the film stru cture changed from alpha-Ti (obtained for a C/Ti flux ratio <0.1), to fcc-T iC (obtained for C flux ratios of 0.2 to 0.5), to an amorphous structure (o btained for C flux ratios >0.5), and that the lattice spacing increased con tinuously with increasing C flux ratio For the polycrystalline TiC films. A maximum microhardness of about 17 GPa was obtained for films deposited at flux ratio of unity. In the sliding wear resistance test, higher abrasive w ear resistance was observed for films deposited with C/Ti flux ratios of mo re than 0.33. The transition of the film structure and composition correspo nds well to the film hardness and abrasive wear behavior. (C) 1999 Elsevier Science S.A. All rights reserved.