In this paper, we studied ZnO-based film bulk acoustic resonator (FBAR) device fabricated on a specially designed multilayered Bragg reflector part. Very thin chromium adhesion layers (0.03 mu m thick) were additionally deposited to improve the quality of the Bragg reflector and some thermal treatments were performed to improve the resonant characteristics of the FBAR device. At the operating frequency of similar to 2.7 GHz, excellent resonant characteristics were observed in terms of return loss and quality factor, and effective electromechanical coupling coefficient.