FULLY DIFFERENTIAL CAPACITIVE ARCHITECTURE FOR MEMS ACCELEROMETER

摘要

A fully differential microelectromechanical system (MEMS) accelerometer configured to measure Z-axis acceleration is disclosed. This may avoid some of the disadvantages in traditional capacitive sensing architectures-for example, less sensitivity, low noise suppression, and low SNR, due to Brownian noise. In one embodiment, the accelerometer comprises three silicon wafers, fabricated with electrodes forming capacitors in a fully differential capacitive architecture. These electrodes may be isolated on a layer of silicon dioxide. In some embodiments, the accelerometer also includes silicon dioxide layers, piezoelectric structures, getter layers, bonding pads, bonding spacers, and force feedback electrodes, which may apply a force to the proof mass region. Fully differential MEMS accelerometers may be used in geophysical surveys, e.g., for seismic sensing or acoustic positioning.