ZnO-Based Film Bulk Acoustic Resonator Devices Feasible for Worldwide Interoperability for Microwave Access Applications

Abstract

In this paper, we describe a novel fabrication technique of ZnO-based film bulk acoustic resonator (FBAR) devices using a new type of multilayered Bragg reflector with very thin chromium (Cr) layers additionally formed between SiO 2 and W layers. Each Cr layer is considered to enhance the adhesion between the SiO 2 and W layers. The fabricated FBAR devices are shown to operate at the frequency range of 2.7 -3.0 GHz, along with good return loss as well as high Q-factors. Furthermore, the effects of bottom electrode thickness on the FBAR device performance are also investigated and compared. This feasibility study indicates that the novel fabrication technique can be useful for future broadband mobile worldwide interoperability for microwave access (WiMAX) applications.