ULTRA-THIN TIO2 FILMS BY A NOVEL METHOD

Ultra-thin TiO2 films were grown by a novel process-successive layer-wise chemisorption-on substrates such as fused quartz and single crystal silicon. Alternate chemisorption of easily hydrolysed TiCl4 and water on a previously hydroxylated substrate surface permitted the synthesis of TiO2 films with thickness precision down to a monolayer. The film thickness is insensitive to growth temperature in the region of 170-240-degrees-C. The cycle thickness (growth rate per cycle) is around 0.27 nm under the growth conditions used. The films have anatase structure and the composition (Ti/O ratio) was shown to be 2. Refractive index of as-deposited films is 2.7 at 632.8 nm.