Undoped ZnO films were deposited on (0 0 1) silicon substrate by radio frequency (RF) magnetron sputtering. It was found that these properties strongly depended on frequency and O-2/Ar gas flux ratio (expressed by k) during the sputtering. The X-ray diffraction patterns of the samples showed sharp diffraction peaks for ZnO (0 0 2), which indicate that the as-sputtered flims were highly c-axis oriented. The band edge emission was observed in photoluminescence spectra at room temperature. The samples grown under certain conditions could generate stronger luminescence of ZnO. Besides, this paper analysed the relation between sputtering technics and crystal quality. The comparison among ZnO films deposited under different sputtering conditions indicated that crystalline quality was improved through changing the RF power and gas flux ratio of O-2 to Ar. (C) 2002 Elsevier Science B.V. All rights reserved.