Behavioral modeling of a monolithically integrated three-axis capacitive accelerometer based on the MetalMUMPs process

In this paper we present behavioral modeling of a monolithically integrated three-axis capacitive accelerometer using the standard MetalMUMPs process. The behavioral modeling is done in order to verify the design with respect to structural and electrostatic performance of the designed three-axis capacitive accelerometer. The proposed accelerometer is 3.2 mm x 3.5 mm in size, designed for sensing the acceleration of 25g in three axes. The mechanical noise floor for in-plane (x and y) and out-of-plane (z) axes is 0.291, 0.316, and 2.84 mu g/root (Hz), respectively. The total sense capacitance along the x, y, and z axes is 68.5 fF, 100 fF, and 6.19 pF, respectively. Sensitivity of 2.568 fF/g, 4 fF/g, and 0.252 pF/g is obtained for in-plane (x and y) and out-of-plane (z) axes, respectively. The resonance frequency for the designed accelerometer is 800 and 2500 Hz for in-plane and out-of-plane axes, respectively. The results obtained by behavioral modeling are compared with the analytical results, which are approximately the same.