Capacitive type pressure sensor
US6877383B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Sep 20, 2002 |
| Grant date | Apr 12, 2005 |
| Priority date | — |
| Expiry date | Dec 30, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L9/0073
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
By sealing a diaphragm with less processes and lower cost and reducing deformation due to remaining stress, a stable and highly reliable pressure sensor construction is proposed. The pressure sensor is low in measurement error and small in floating capacitance and leakage current and good in characteristic. As a means to attain the above object, a polycrystalline silicon diaphragm is sealed with a silicon oxide film deposited through a LPCVD method and then completely covered. The diaphragm is placed on a surface of a semiconductor substrate with a nearly constant gap of 0.15 to 1.3 μm, and has difference-in-grade constructions of a deformation reducing means due to remaining stress.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.