A high sensitivity micromachined accelerometer with an enhanced inertial mass SOI MEMS process

This paper provides an enhanced inertial mass SOI MEMS process for the fabrication of a high sensitivity micromachined accelerometer. In the proposed process, the handle layer of the SOI wafer is used as an enhanced inertial mass, in this way, the inertial mass of the accelerometer can increase 5-15 times. Therefore, the sensitivity of the MEMS accelerometer can be significantly increased. In this paper, an in-plane single-axis accelerometer is designed firstly. And then, the accelerometer is fabricated in a low resistivity SOI wafer with 60μm thickness device layer and 400μm thickness handle layer through the developed enhanced inertial mass SOI MEMS process. The sensitivity of the fabricated MEMS accelerometer is 2.257V/g, the linearity of output is within 0.5%,and the power spectral density of the noises is as low as 6.79uV/ Hz.