Deposition of thin film ZnO with characteristics close to bulk crystal ZnO

Abstract

Abstract Excellent films of piezoelectric ZnO with characteristics close to bulk crystal ZnO have been reliably deposited by rf planar magnetron sputtering. The successful deposition has resulted from the optimization of the sputtering process parameters, such as substrate temperature, gas pressure, target power density, etc. The c-axis orientation of the films has been tested with normal scans and rocking curves of X-ray diffraction. A sharp peak with high intensity at 34.22° (corresponding to the (002) plane of the ZnO films) typically has a full-width-at-half-maximum of 0.19°, coinciding with that of the bulk crystal ZnO. Rocking curves have a very small standard deviation of 0.11°, indicating highly uniform distribution of the c-axis orientation among various crystallites. Post-deposition annealing has been found to improve the c-axis orientation of the ZnO films and to increase the crystallite sizes.