Hydrothermal epitaxy of highly oriented TiO2 thin films on silicon

Highly oriented thin films (0.15 μm) of titania on Si (100) substrates have been prepared first by hydrothermal treatment of TiO42− solution (0.6–1.2M) at relatively low temperatures. Films made at 100–200 °C contain only the anatase phase with (112) orientation, adhere well to the substrates. The hydrothermal temperature, time, and the pH value of TiO42− solution are the critical parameters determining the formation of films.