MONOLITHIC SILICON ACCELEROMETER

A monolithic silicon micromechanical accelerometer, which is particularly well suited for integration with other mechanical and electrical components, and is about 0.75 mm2 in area, is described. Four electrodes are built into the structure in the manner of buried layers and are used to effect a differential capacitance readout and electrostatic torquing for closed-loop operation. Current performance is less than 500 ppm scalefactor error. An important constraint was process compatibility with Draper Laboratory's micromechanical gyroscope, so that both can eventually be made on the same chip. © 1990.