Cross-shaped PnC for anchor loss reduction of thin-film ALN-on-silicon high frequency MEMS resonator

This paper presents an approach to reduce the anchor loss of thin-film-piezoelectric-on-silicon (TPoS) high frequency MEMS resonator. The PnC prevents acoustic wave to propagate through the support tethers, and reflects it back to the resonator body, which serves to increase the store energy, and then enhances the quality factor (Q). This design discussed the effect of the tether width, tether length, and impact of the design geometry on bandgap and the quality factor. The desired design of PnCs provides wide bandgap and high quality factor by introducing cross-shaped of 2D phononic crystal externally on anchors. The design provides a bandgap up to 230MHz and increases the quality factor from 21,180 to 221,536. The technique provides a high quality factor than the previous work.