Abstract ZnO thin films were deposited on glass and p-Si (100) wafers using the metalorganic source, diethylzinc (Zn (C 2H 5) 2), and N 2O gas by plasma enhanced CVD (PECVD). The growth rate, crystal perfection and c-axis orientation of ZnO thin films deposited under various conditions were determined using SEM, XRD and X-ray rocking curve. The substrate temperature and rf power density ranged from 100 to 300°C and from 50 W (0.16 W/cm 2) to 250 W (0.80 W/cm 2), respectively. The degree of the c-axis preferred orientation of ZnO thin films was governed by the rf input power at the same substrate temperature. The growth rate was affected by both substrate temperature and rf-input power. The activation energies to deposit ZnO thin films at an rf input power of 200 and 250 W were 3.1 and 1.9 kJ / mol, respectively. Even at a low temperature of 200°C, a high degree of c-axis preferred orientation of ZnO thin films was achieved at an rf power of 200 W.