Preparation of SrTiO3 thin films by the liquid phase deposition method

Successful preparation of strontium titanate (SrTiO3; STO) thin films has been realized by the liquid phase deposition method. The STO precursor solid thin films with close-packed grains smaller than 200 nm were fabricated from an aqueous solution of Sr(NO3)2/(NH4)2TiF6/H3BO3=1/1/3 (molar ratio) at 50 °C on a Si substrate. X-ray photoelectron spectroscopy analysis showed that the as-deposited film contained fluorine as an impurity, which could be completely eliminated by annealing at 500 °C in air, accompanying the crystallization of the as-deposited amorphous thin film into perovskite-type STO.