This paper reports the novel growth procedure for ZnO films on Si substrates by metalorganic vapor phase epitaxy. This can lead to conductive and inexpensive substrates for ZnO, which have been obstructed by the difficulty of growing ZnO films on Si due to easy oxidation of Si substrate surface with an oxygen source. Our proposal is based on the following three step growth, that is, (i) the growth of initial nucleation layer, (ii) the successive growth of recovery layer, and (iii) the growth of main layer. As a result, the three step growth is found to be a promising procedure to grow ZnO films on Si substrates with smooth surface. The increase of VI/II ratio for the main layer growth is also effective for further improvement of the surface morphology. (c) 2006 Published by Elsevier B.V.