Single-side microelectromechanical capacitive accelerometer and method of making same

US6718605B2 · kind B2 · utility

Assignee

• THE REGENTS OF THE UNIVERSITY OF MICHIGAN · US

Inventors

• Navid Yazdi · Ann Arbor, US
• Khalil Najafi · Ann Arbor, US
• Arvind S. Salian · Chandler, US

Key dates

• Filing date: Jun 21, 2001
• Grant date: Apr 13, 2004
• Expiry date: Mar 25, 2022

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T29/4913
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A high sensitivity, Z-axis, capacitive microaccelerometer having stiff sense/feedback electrodes and a method of its manufacture on a single-side of a semiconductor wafer are provided. The microaccelerometer is manufactured out of a single silicon wafer and has a silicon-wafer-thick proof mass, small and controllable damping, large capacitance variation and can be operated in a force-rebalanced control loop. One of the electrodes moves with the proof mass relative to the other electrode which is fixed. The multiple, stiffened electrodes have embedded therein damping holes to facilitate force-rebalanced operation of the device and to control the damping factor. Using the whole silicon wafer to form the thick large proof mass and using thin sacrificial layers to form narrow uniform capacitor air gaps over large areas provide large-capacitance sensitivity. The manufacturing process is simple and thus results in low cost and high yield manufacturing.