Abstract
ZnO thin films on glass substrate were deposited by RF sputter with various $Ar/O_2$ gas ratio. Crystallinities, surface morphologies, and electrical properties of the films were investigated by XRD(x-ray diffractometer), and SEM (scanning electron microscopy) analyses. The facing targets sputtering system can deposit thin film at plasma free condition and change the deposition condition in wide range. We suggested that a very suitable $Ar/O_2$ gas of ratio should be 50/50 for preparation of high quality ZnO films with good C-axis orientation.