Recent VLSI requires materials with high dielectric constant in order to reduce their storage capacitor areas. We attempted to form a tantalum oxide film from Ta(OCH3)5 at a low temperature by photo-CVD method. Our evaluation shows that the photo-CVD film obtained in this study has good step coverage, high dielectric constant (20–24), and low leakage current, and is superior to the thermal-CVD film in various characteristics.