Fully differential capacitive pressure sensor including stacked sensor and reference capacitors

US11885705B2 · kind B2 · utility

Assignee

• Infineon Technologies AG · DE

Inventors

• Athanasios Kollias · Munich, DE
• Bernhard Winkler · Birkenfeld, DE

Key dates

• Filing date: Aug 2, 2022
• Grant date: Jan 30, 2024
• Expiry date: Aug 2, 2042

Classification

• Technology area (CPC G): Physics
• CPC primary: G01L13/025
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Pressure sensors include stacking of sensor capacitors on top of reference capacitors. A pressure cavity may be extended below a bottom electrode. The pressure sensors may include a mechanical link of a top membrane with the bottom electrode in order to form a dual membrane, or a mechanical link of the top membrane, the bottom electrode and an intermediate electrode within a cavity. A pressure sensor includes a first and second pressure sensing portions, each including a first and second rigid electrodes, and a deflectable membrane structure. The second rigid electrode is between the first rigid electrode and the deflectable membrane structure arranged in a vertical configuration. The first and second rigid electrodes of the first and second pressure sensing portions form respective reference capacitors, and the second rigid electrodes and the deflectable membrane structures form respective sensing capacitors.