Semiconductor pressure sensor and pressure sensing device
US6892582B1 · kind B1 · utility
Assignees
Inventors
Key dates
| Filing date | Aug 20, 1999 |
| Grant date | May 17, 2005 |
| Priority date | — |
| Expiry date | Aug 20, 2019 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB81C2203/0145
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The object of the present invention is to propose an etch channel sealing structure characterized by excellent impermeability to moisture and resistance to temporal change of the diaphragm in the pressure sensor produced according to the sacrificial layer etching technique, and to provide a pressure sensor characterized by excellent productivity and durability. After a very small gap is formed by the sacrificial layer etching technique, silicon oxide film is deposited by the CVD technique or the like, thereby sealing the etch channel. Further, impermeable thin film of polysilicon or the like is formed to cover the oxide film.This allows an etch channel sealing structure to be simplified in the pressure sensor produced according to the sacrificial layer etching technique, and prevents entry of moisture into the cavity, thereby improving moisture resistance. Moreover, sealing material with small film stress reduces temporal deformation of the diaphragm.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.