An All-Silicon Double Differential MEMS Accelerometer with Improved Thermal Stability

Although MEMS technologies are developing rapidly, MEMS accelerometers still can not compete with macro electro-mechanical accelerometers in the performance of bias temperature stability and long-term bias repeatability. Unlike former reported literatures trying to use innovative package technologies or self-calibration methods to solve this issue, this work was attempting to employ double differential configuration to improve accelerometers' thermal stability. Slanted-beam sandwich structures were chosen to construct a novel double differential scheme, and this scheme is believed to be more suitable for high-precision and high-stable applications. The working principle and Finite Element Modeling (FEM) of our proposed accelerometer were presented. Then, the proposed fabrication processes and major fabrication challenges were also addressed. Preliminary measurement results of the discrete version experimentally demonstrate the significant improvement of the accelerometer's thermal stability.