Preferential growth of thin rutile TiO2 films upon thermal oxidation of sputtered Ti films

Abstract

Thin rutile TiO2 films with (200) preferred orientation were fabricated by thermal oxidation of sputtered Ti metal films on a fused silica substrate. Experimental results indicate that the preferential crystal growth of (200)-oriented TiO2 is determined by the competition between surface free energy and strain energy. The highly crystalline Ti film with (002) orientation has a greater tendency to promote the growth of (200)-oriented TiO2 However, for the amorphous and low crystalline Ti films, orientation of the crystallites evolved in the resulting TiO2, film tends to be randomly distributed. The extent of preferential crystal growth of TiO2 (200) plane can be enhanced by decreasing the annealing temperature or the thickness of Ti film. (C) 2002 Elsevier Science B.V All rights reserved.