Acoustic Reflectors for Anchor Loss Reduction of Thin Film Piezoelectric on Substrate Resonators

This paper describes a fish scale reflector (FSR) structure in the anchoring boundaries to improve the quality factor of thin-film piezoelectric-on-substrate (TPoS) resonators. A 2D fishscale reflector is designed and employed on the anchoring boundaries aiming to suppress the acoustic energy leakage through the tether to the supporting substrate. Finite element method (FEM) simulated results revealed that compared to the conventional resonators, the resonators with single reflector and fish scale reflector has improved the quality factor. In this regard, the Q of the fish scale reflector (FSR) resonator achieved a 3.2-fold improvement (i.e. Q
_anc
=16366) compared with the conventional(C) design (i.e. Q
_anc
=5083) and an almost 2.3-fold improvement compared with the single reflector (SR) structure (i.e. Q
_anc
= 7044).