Development of High-Quality FBAR Devices for Wireless Applications Employing Two-Step Annealing Treatments

Abstract

In this letter, a new two-step annealing technique is presented that can more effectively improve the resonance characteristics of the film bulk acoustic wave resonator (FBAR) devices in terms of return loss, Q-factor, and effective electromechanical coupling coefficient (K(eff)(2)). In the case of the SMR-type FBAR devices, the use of this approach has considerably improved the resonance performance (similar to 8000 of Q-factor value, similar to 2% of K(eff)(2)) at the operating frequency of similar to 1.8 GHz, as compared to the conventional annealing techniques.