Preparation of PbTiO3 thin film by laser-assisted cvd and its electrical properties

Abstract

PbTiO3 thin films were prepared on Pt/SiO2/Si substrates by KrF excimer laser-assisted CVD. Dielectric constant of the film increased with increasing deposition temperature. The film with almost same dielectric constant as PbTiO3 bulk ceramics was deposited at 450°C with the laser irradiation. This temperature was 100°C lower than that of unirradi-ated film (550°C). Especially, laser-irradiated film had twice as high dielectric constant as unirradiated film at 450°C. Laser-irradiated film deposited at 450°C contained smaller fraction of amorphous phase than laser-unirradiated film. Moreover, the laser irradiated film kept almost constant dielectric constant of 170 down to 350nm in thickness. This is originated to the nonexistence of the layer with low dielectric constant adjacent to the substrate, which was observed for the unirradiated film deposited at 570°C. Laser irradiation is considered to promote the surface reaction and the growth of the highly crystallized nuclear on the substrate from the initial stage of the film deposition process.