A 3-D Parallel-Plate MEMS Accelerometer with a Gold Proof Mass

This paper presents a low-noise and high-sensitivity surface-micromachined 3-axis MEMS accelerometer for sub-mG (1 G=9.8 m/s
²
) sensing. 3-D parallel-plate (3D-PP) electrodes for a single high-density proof mass made of gold are proposed for the first time, and the device characteristics are experimentally evaluated. When compared with conventional devices, the Brownian noise is nearly three orders of magnitude smaller and the capacitance sensitivity is two-to-three orders of magnitude larger.