A thin film patterning method may include forming a thin film by coating a precursor solution containing a precursor of metal oxide onto a substrate, soft baking the thin film, exposing the thin film to light by using a photomask, developing the thin film, and hard baking the developed thin film. The precursor may include metal acetate, for example, a zinc acetate-based material, and the metal oxide thin film may include zinc oxide (ZnO).