Spider Web-Shaped Phononic Crystals for Quality Factor Improvement of Piezoelectric-on-Silicon MEMS resonators

摘要

This paper shows the approach to significantly reduce the energy dissipation of thin-film piezoelectric-on-silicon (TPoS) micro-electro-mechanical systems (MEMS) resonator by employing a 2D innovative lightweight spider web-shape phononic crystals (PnC) structure. An AlN-on-Si MEMS resonator, which is working at 40 MHz 5th-order width-extensional (WE) resonant mode, is selected to investigate the energy dissipation reduction by the proposed PnC. According to the simulation results, the proposed PnC structure shows a complete acoustic bandgap from 37 MHz to 44 MHz and can significantly reduce the energy loss. Moreover, the anchor loss (Qanc) of the resonator reached 2, 090, 000 at 40.03 MHz.