Exploring the Q-factor limit of temperature compensated CMOS-MEMS resonators

This work presents a study on the quality factor (Q-factor) of the passively temperature compensated CMOS-MEMS resonators through the collected material/experimental database and finite-element (FEM) simulation. By adapting an anchor-loss-free double-ended tuning fork (DETF) resonator design, the intrinsic material loss is expected to be the major loss mechanism in CMOS-MEMS resonators that limits the maximum Q-factor below 3,400 at the frequency of interest (300 kHz - 3 MHz). The highest Q-factor of 3,029 is measured in a 1.17-MHz DETF resonator, which is in good agreement with the theoretical prediction. Moreover, the increase of Q-factor at high temperature is also observed, which makes the proposed resonator very attractive for oven-controlled CMOS-MEMS oscillator applications.