Preparation and piezoelectric analysis of the multilayer films for fbar

A multilayered structure of Al/ZnO/Al/DLC for FBAR was prepared in this research, and its piezoelectric performance was measured. The results show that DLC film with high sp³ content can be prepared at room temperature by using ECR-CVD system with the power of 1200W, the total pressure of 1Pa, as well as the CH4 and Ar gas ratio of 1-9. High c-axis oriented ZnO films can be prepared with the optimized process parameters, and their performance can be further improved by annealing treatment. The piezoresponse amplitude and phase of the ZnO films were measured by using piezoresponse force microscopy (PFM). The results indicate that the ZnO film prepared at 250°C temperature has good piezoelectric performance, meeting the requirement of the piezoelectric layer for FBAR.