Method of fabricating a piezoresistive pressure sensor
US6417021B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 23, 1999 |
| Grant date | Jul 9, 2002 |
| Priority date | — |
| Expiry date | Sep 23, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L9/0055
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The pressure sensor is integrated in an SOI (Silicon-on-Insulator) substrate using the insulating layer as a sacrificial layer, which is partly removed by chemical etching to form the diaphragm. To fabricate the sensor, after forming the piezoresistive elements and the electronic components integrated in the same chip, trenches are formed in the upper wafer of the substrate and extending from the surface to the layer of insulating material; the layer of insulating material is chemically etched through the trenches to form an opening beneath the diaphragm; and a dielectric layer is deposited to outwardly close the trenches and the opening. Thus, the process is greatly simplified, and numerous packaging problems eliminated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.