Design, modelling and system level simulations of DRIE-based MEMS differential capacitive accelerometer

The paper presents design, analytical modelling and system level simulations of a highly sensitive single-axis in-plane Micro-Electro-Mechanical-Systems (MEMS) differential capacitive accelerometer. The designed accelerometer is Deep-Reactive-Ion-Etching (DRIE)-based with Silicon-on-Insulator (SOI) wafer technology. Analytical models have been derived for frequency as well as transient response analysis. For system level simulations, accelerometer model were extracted from MEMS+(R) and further integration for the readout electronics were performed using MATLAB Simulink (R) module. The accelerometer has response time of 0.7 ms and settling time of 5 ms. The accelerometer has the displacement sensitivity of 0.121 mu m/g, capacitive sensitivity of 225 fF/g and electrical sensitivity of 0.34 V/g for MS3110 capacitive to voltage readout circuitry, with a resolution of better than 1 mg. The device shows very less non-linearity ( 0.3%) in the operating range of +/- 5 g with a bandwidth of 100 Hz. The simulation results of designed open-loop readout circuitry to read the applied acceleration in terms of voltage are also presented.