J. Phys. IV France 02 (1991) C2-557-C2-562
GRAIN REFINEMENT OF CVD TiC LAYERS BY AlCl3, ZrCl4 AND BCl3 IMPURITIESA. OSADA1, M. DANZINGER2, R. HAUBNER2 and B. LUX2
1 Mitsubishi Materials Corporation, 1-27-20 Nishi-Shinagawa, Shinagawa-ku, Tokyo 141, Japan
2 Institute for Chemical Technology of Inorganic Materials, Technical University Vienna, Getreidemarkt 9/161, A-1060 Vienna, Austria
The influence of small amounts of AlCl3, ZrCl4 and BCl3 on CVD of TiC with a TiCl4/H2/CH4 gas mixture under reduced pressure was investigated. Grain refinement of TiC coatings could be obtained by adding dopant compounds at suitable concentrations. Their interactions are explained by the formation of co-deposited phases which interfere with the growth of TiC crystals and promote surface nucleation. The effectiveness of dopants to decrease the grain size is explained by the formation of thin films on the growing TiC crystals having a different chemical bonding than TiC.
© EDP Sciences 1991