A Ti layer with a thickness of 250nm was successfully deposited onto the surface of diamond substrates using the radio-frequency magnetron sputtering technique. AES analysis indicates that the Ti layer reacted with the diamond substrate to form TiC species on the interface during the deposition. The interface diffusion and reaction between the Ti layer and the diamond substrate were promoted significantly by an annealing treatment at a temperature range of 200-600C in a high vacuum. The Auger line shapes of Ti LMM and C KLL confirmed the formation of TiC species, which results from the interface diffusion and reaction. The interface diffusion and reaction were intensified significantly with the rising annealing temperature. However, the Ti layer was considerably oxidized by residual oxygen when the annealing temperature was over 500C. A prolonged annealing time at 400C could not only promote the interface diffusion and reaction greatly, but could also prevent oxidation of the Ti layer. Annealing at a relatively low temperature for a long time may be a good method with which to intensify the interface diffusion and reaction. The apparent activation energy of interface diffusion and reaction was about 12.3kJ/mol.

The Interface Diffusion and Chemical Reaction between a Ti Layer and a Diamond Substrate. Zhu, Y., Zheng, B., Yao, W., Cao, L.: Diamond and Related Materials, 1999, 8[6], 1073-8