Polycrystalline silicon pressure transducer
US3938175A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 25, 1974 |
| Grant date | Feb 10, 1976 |
| Priority date | — |
| Expiry date | Nov 25, 1994 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49103
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A semiconductor pressure transducer having a polycrystalline silicon diaphragm providing an extremely pressure sensitive and temperature stable device, and a method of making the same. The polycrystalline silicon can easily be vapor deposited on an etch resistant layer covering a surface of a wafer or base, preferably monocrystalline silicon. Such vapor deposition of the polycrystalline silicon more accurately and consistently defines the thickness of the diaphragm than can be obtained by grinding or etching. A pressure responsive resistor formed in the diaphragm is automatically electrically isolated by the comparatively high resistivity of the polycrystalline silicon. Accordingly, PN junction isolation and passivating oxides on the diaphragm are not required thereby resulting in increased temperature stability.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.