ZnO films are prepared by plasma enhanced chemical vapor deposition (PECVD), using carbon dioxide-hydrogen gas and diethylzinc gas as reactant sources. Carbon dioxide reacts with hydrogen in the plasma charmer to produce oxygen source. Crystallographic properties and surface morphology of the films are characterized by X-ray diffraction (XRD) and atomic force microscopy (AFM). The results indicate that the wurtzite structure of ZnO thin films with a strong c-axis orientation is successfully deposited on Si substrate. AFM images show that the grains arrange regularly and roughness of the surface is very small. A type emission peak at 380 nm of ZnO is also observed from photoluminescence (PL) spectrum.