A 10 MHz thin-film piezoelectric-on-silicon MEMS resonator with T-shaped tethers for Q enhancement

Abstract

Thin-film piezoelectric-on-silicon (TPoS) MEMS (i.e. micro-electro-mechanical system) resonators have attracted much attention due to its unique features, such as CMOS-compatible fabrication process, however, its applications require, in particular, the enhancement of quality factor (Q). Herein, a 10 MHz TPoS MEMS resonator with T-shaped tethers coupled with reflecting blocks was proposed. Finite-element analysis was employed for modeling the proposed TPoS resonators to investigate the underlying mechanism of Q enhancement by the introduction of T-shaped tethers and reflecting blocks. It was figured out that the combination of T-shaped tethers and reflecting blocks can significantly reduce the energy leakage through the anchor substrate by reflecting mechanical waves and trapping the energy. The measured results of fabricated TPoS resonators further verified the effectiveness of Q enhancement by the as-presented new design, and the insertion loss and the Q were improved to 3.27 dB and 1903, respectively.