Advanced CMOS–MEMS Resonator Platform

Deep-submicrometer-gap CMOS-MEMS “composite” resonators fabricated using 0.18- μm-1-poly-6-metal foundry CMOS technology have been demonstrated for the first time to substantially improve their electromechanical coupling coefficient, hence leading to a motional impedance of only 880 kΩ at 15.3 MHz. A simple maskless wet release process has been successfully transferred from a 0.35- μm platform to an advanced 0.18-μm version, capable of offering enhanced gap spacing and transduction area for CMOS-MEMS resonators monolithically integrated with high-performance CMOS circuitry. This proposed platform offers ease of use, fast turnaround time, low cost, convenient prototyping, and inherent MEMS-circuit integration, therefore showing great potential toward future integrated sensing and single-chip RF applications.