Bi-axial highly sensitive ±5g polysilicon based differential capacitive accelerometer

This paper demonstrates the design and simulation of a 2-axis capacitive accelerometer. The design utilizes a simple comb structure to detect capacitance change with a minimum gap spacing of 0.9 μm. By optimizing the design and anti-gap spacing, the device is designed to yield high capacitance change with the proof mass displacement. Initial simulation results show a displacement sensitivity of 0.02μm/g (g=9.8 m/s2) and a differential capacitance sensitivity (scale factor) of 68 fF/g. The sensitivity achieved is best among the devices of its range (± 5g) and dimensions (2×2mm2). This device is being fabricated by GlobalFoundries-Singapore.