This work fabricates a laminated-suspension microelectromechanical filter, respectively, by a fully compatible CMOS 0.6 μm single poly triple metal (SPTM) process and CMOS 0.35 μm single poly quadri-metal (SPQM) process. Experimentally, due to the top metal layer being used as the etch-resistant mask during the subsequent dry etching. Therefore, this study performs maskless etching with plasma and obtains excellent results including high selectivity and full release of the structure. Additionally, the microelectromechanical filter can be driven by applying low-voltage of around 5 V and a measured center frequency of around 13.1 kHz and a quality factor of around 1871 were obtained for a single-comb resonator operated in air. The filter successful proposed herein has a monolithic integration capability with the relative electric circuits in the standard CMOS 0.35 μm process.
Sensors and Actuators A: Physical 90(1-2), pp.148-152