Light induced chemical vapour deposition of titanium oxide thin films at room temperature

High resolution patterned deposition of titania is achieved by light induced chemical vapour deposition (LICVD), by imaging a mask onto a glass substrate. A long pulse XeCl Excimer laser (308 nm) provides, by perpendicular irradiation, the energy to convert titanium tetraisopropoxide (TTIP) vapour into titanium dioxide films, in an oxygen atmosphere, on unheated glass substrates. The amorphous titania deposits contain about 6% carbon contamination according to X-ray photoelectron spectroscopy (XPS) measurements. The deposition rate increases with increasing laser fluence until a maximum value is reached, then remains constant over a wide range, and finally decreases with further fluence increase due to titania ablation or thermal effects. The film thickness increases linearly with the number of pulses after a nucleation period. The strong influence of the laser pulse repetition rate on the growth rate and the thickness profile are reported.