The Suppression Mechanism of Parasitic Capacitance for Comb Capacitor Fabricated with Silicon-On-Insulation

This paper establishes theoretical circuit and electrostatic current multi-physical field simulation models for a typical comb capacitor fabricated with silicon-on-insulation. The influence of related electrical parameters and conditions on equivalent capacitance is revealed by analytical solution and simulation, and several methods are proposed to suppress the interference of parasitic capacitance on ideal capacitance, such as high-resistivity substrate Si, relatively high-frequency excitation, and grounded substrate Si. The models and methods proposed in this paper can provide theoretical guidance for the design and suppression of parasitic capacitance of MEMS (Micro-Electro-Mechanical System) capacitive sensors.