US4945769A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semiconductive structure useful as a pressure sensor
Assignee: Delphi Technologies Inc
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Filing: 1989-03-06
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Granted: 1990-08-07
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Expires: 2009-03-06
Abstract
Abstract A pressure sensor uses a monocrystalline silicon chip that has a diaphragm portion in which strain gages are formed that overlie a buried cavity. The cavity is formed by a single sided semiconductor fabrication process that includes a pair of preferential etching steps and an epitaxial deposition step.
Inventors
- 👤 Diane W. Sidner
- 👤 Douglas J. Yoder
- 👤 David E. Moss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:08
CPC Classifications
G; G01; G01L; G01L9/00; G01L9/0041; G01L9/0051; G01L9/0052; G01L9/0054; G01L9/0042
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
76 words
A pressure sensor comprising: a monocrystalline semiconductive chip including within its bulk a sealed buried cavity whose lateral extent defines a surface of an overlying diaphragm layer which includes an epitaxial moncrystalline portion and which extends to a first surface of the chip; means forming at least one strain gage in a portion of the diaphragm layer; and means in said surface surrounding the diaphragm layer for forming circuit elements for interconnection with said strain gage(s).
Claim 2
Dependent Claim
76 words
A pressure sensor comprising: a monocrystalline semiconductive chip including within its bulk a sealed buried cavity whose lateral extent defines a surface of an overlying diaphragm layer which includes an epitaxial moncrystalline portion and which extends to a first surface of the chip; means forming at least one strain gage in a portion of the diaphragm layer; and means in said surface surrounding the diaphragm layer for forming circuit elements for interconnection with said strain gage(s).
Claim 3
Dependent Claim
86 words
A semiconductive structure comprising: a monocrystalline silicon chip including within its bulk an enclosed buried cavity whose lateral extent defines a surface of an overlying monocrystalline silicon diaphragm which includes an epitaxial monocrystalline silicon portion sealing the cavity, and which extends to a first surface of the chip; means forming four piezoresistors in a portion of the diaphragm layer and interconnecting them to form a Wheatstone bridge; and means in said chip surrounding said diaphragm layer for forming circuit elements for interconnection with the Wheatstone bridge.
Claim 4
Dependent Claim
86 words
A semiconductive structure comprising: a monocrystalline silicon chip including within its bulk an enclosed buried cavity whose lateral extent defines a surface of an overlying monocrystalline silicon diaphragm which includes an epitaxial monocrystalline silicon portion sealing the cavity, and which extends to a first surface of the chip; means forming four piezoresistors in a portion of the diaphragm layer and interconnecting them to form a Wheatstone bridge; and means in said chip surrounding said diaphragm layer for forming circuit elements for interconnection with the Wheatstone bridge.
Claim 5
Dependent Claim
91 words
A semiconductive pressure sensor structure comprising: a monocrystalline silicon chip including within its bulk an enclosed buried cavity whose lateral extent defines a surface of an overlying silicon diaphragm layer, said diaphragm layer including an epitaxial monocrystalline silicon portion which seals said enclosed cavity, and said diaphragm layer extending to a first surface of the chip; means forming at least one pressure sensitive device in a portion of the diaphragm layer; and means in said surface surrounding the diaphragm layer for forming circuit elements for interconnection with the pressure sensitive device.
Claim 6
Dependent Claim
91 words
A semiconductive pressure sensor structure comprising: a monocrystalline silicon chip including within its bulk an enclosed buried cavity whose lateral extent defines a surface of an overlying silicon diaphragm layer, said diaphragm layer including an epitaxial monocrystalline silicon portion which seals said enclosed cavity, and said diaphragm layer extending to a first surface of the chip; means forming at least one pressure sensitive device in a portion of the diaphragm layer; and means in said surface surrounding the diaphragm layer for forming circuit elements for interconnection with the pressure sensitive device.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-08-06 | 1994-02-05 | 1994-08-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-08-06 | 1998-02-05 | 1998-08-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-08-06 | 2002-02-05 | 2002-08-07 | $7700.00 | Window Closed / Lapsed |