Jae-young Lee

Design and Fabrication of ZnO-Based FBAR Microwave Devices for Mobile WiMAX Applications

In this letter, we present the design and fabrication of a novel ZnO-based film bulk acoustic wave resonator (FBAR) microwave devices. The novel FBAR devices employ a new-type of Bragg reflector with very thin chromium (Cr) layer formed between SiO2 and W films. The Cr layer seems to enhance the adhesion between SiO2 and W layers. The novel FBAR devices show good return losses (S11) and high Q-factors at the frequency range of 2.7-3.0 GHz. This approach will be very helpful for mobile worldwide interoperability for microwave access applications.

A new fabrication technique for 2.75 GHz ZnO-based FBAR devices

We for the first time present a new fabrication technique of ZnO-based FBAR devices using a multi-layered Bragg reflector. To improve the resonance performance, 0.03?m-thick chromium (Cr)-adhesion layers were inserted into the Bragg reflector and also thermal treatments were made to the devices. At operating frequency of about 2.75 GHz, very high return loss values and quality factor (Q) were observed under an optimum thermal annealing condition.