Deposition of ZnO thin films by MOCVD using ultrasonic nebulization

ZnO thin films were deposited on the soda lime glass substrates at the low substrate temperatures of 225 similar to 325 degrees C by the MOCVD using ultrasonic nebulization and their deposition characteristics were investigated. Zinc acetylacetonate, which is not appropriate to the source material in normal CVD because of high melting point, was used as a precursor for Zn source. Deposition rate was controlled by the surface reaction rate up to 275 degrees C and decreased at the deposition temperatures over 275 degrees C due to the homogeneous reaction of source gas in the gas phase. All the films deposited were crystalline and (002) preferred orientation of the films increased with the deposition temperature. Resistivity of the films was highly dependent on the deposition temperature and 1.0 x 10(0)similar to 2.2 x 10(3) Omega . cm. The average transmittance of films in the visible range was over 90% and the optical band gap of the films was 3.28 regardless of deposition temperature.