LOW-PARASITIC CAPACITANCE MEMS INERTIAL SENSORS AND RELATED METHODS

• Main Authors: GREGORY JEFFREY, BLACKMER CHARLES, POKROVSKIY NIKOLAY, KAANTA BRADLEY
• Format: Patent
• Language: Chinese; English
• Published: 25.02.2022
• Subjects: GYROSCOPIC INSTRUMENTS; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT; MEASURING; MEASURING DISTANCES, LEVELS OR BEARINGS; MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION,OR SHOCK; MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICALDEVICES; MICROSTRUCTURAL TECHNOLOGY; NAVIGATION; PERFORMING OPERATIONS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY; PHYSICS; PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTUREOR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS; SURVEYING; TESTING; TRANSPORTING

Microelectromechanical system (MEMS) inertial sensors exhibiting reduced parasitic capacitance are described. The reduction in the parasitic capacitance may be achieved by forming localized regions of thick dielectric material. These localized regions may be formed inside trenches. Formation of trenches enables an increase in the vertical separation between a sense capacitor and the substrate, thereby reducing the parasitic capacitance in this region. The stationary electrode of the sense capacitor may be placed between the proof mass and the trench. The trench may be filled with a dielectric material. Part of the trench may be filled with air, in some circumstances, thereby further reducing the parasitic capacitance. These MEMS inertial sensors may serve, among other types of inertial sensors, as accelerometers and/or gyroscopes. Fabrication of these trenches may involve lateral oxidation, whereby columns of semiconductor material are oxidized. 描述表现出减小寄生电容的微机电系统(MEMS)惯性传感器。寄生电容的减小可通过形成厚介电材料的局部区域来实现。这些局部区域可以在