Electrostatic forces and their effects on capacitive mechanical sensors

This paper describes the electrostatic forces developed between the plates of capacitive mechanical sensors built in crystalline silicon and their effects on the measurement and the fabrication process. In single capacitive sensors the electrical forces can introduce offset errors in the measuring process, or can cause the collapse of the sensing structure or jeopardize the functionality of the final device due to the sticking or even bonding of the movable parts. Also it is investigated how the limits are affected when scaling down the dimensions of the sensors. Finally, some solutions to avoid the negative effects of the electrostatic forces are proposed.