Semiconductor pressure sensor means and method
US4889590A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 27, 1989 |
| Grant date | Dec 26, 1989 |
| Priority date | — |
| Expiry date | Apr 27, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/24479
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A piezo-resistive pressure sensor element is formed in the front face of a silicon wafer. A thin diaphragm is formed under the sensing element by anisotropically etching a cavity from the rear face of the wafer. The rear face (cavity-side) rupture pressure of the silicon diaphragm is at least doubled by subjecting the anisotropically etched cavity to a mild isotropic etch. This substantially improves the cavity-side over-pressure rating of the finished pressure sensor without any significant change in the device sensitivity or allows higher sensitivity to be obtained for the same over-pressure rating or intermediate combinations thereof.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.