Diode Integrated Capacitive Accelerometer with Reduced Structural Distortion

This paper describes the development of diode integrated capacitive accelerometer with reduced structural distortion. To obtain high sensitivity in capacitive sensors, narrow capacitor gaps are needed. To realize such narrow capacitor gaps, it is important to reduce a structural distortion during anodic bonding process. We studied the anodic bonding process to reduce the structural distortion, and found that it is effective to use thick glass and optimum bonding temperature. The accelerometer has a surrounding seismic mass suspended with four thin beams formed in the middle of the wafer thickness. A diode- bridge circuit to detect differential capacitances was integrated on the silicon chip.