Microdevice array design and fabrication in monolithic MEMS SoC

This Letter presents a simple approach to fabricate the monolithic MEMS system on chip by means of adopting the 0.35 mu m bipolar-CMOS-DMOS process with a single 3 mu m-thick metal structure layer. The performance specifications are simply defined by the geometries of the metal proof-mass and the spring in these designs. The proposed designs include the out-of-plane and in-plane mechanical structures in different matrix arrays. No stress-induced deformation was observed in each single device within wide operation ranges of temperature. Simulation data of frequency responses at 14.22 and 2.71 kHz fit well with the measurement ones in each design. This potentially provides a novel advantage for the scalability to further integrate flattened microstructures with on-chip functional circuits for enhancing the system performance. The authors successfully demonstrate a platform for simplifying the designs that are applicable for inertial sensors, optical mirrors and biodetectors.