Patent US5225377A successfully refreshed from Google Patents.
US5225377A
Expired / Lapsed
US
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Method for micromachining semiconductor material
Assignee: Honeywell Inc
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Filing: 1991-05-03
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Granted: 1993-07-06
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Expires: 2011-05-03
Abstract
Abstract A structure is formed from two layers of material having opposite conductivity types. A first region is formed within the structure, and extends at least in part into a layer to be etched. A surface of the structure is then masked and etched. The result is a microstructure which varies with the conductivity type and geometry of the region formed and etchant used.
Inventors
- 👤 John R. Hines
- 👤 Ralph H. Johnson
- 👤 Richard Kirkpatrick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 20:46
CPC Classifications
G; G01; G01L; G01L9/00; G01L9/0041; G01L9/0042; Y; Y10; Y10S; Y10S438/00; Y10S438/914; Y10S438/924
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
63 words
A method of forming a pressure transducer, comprising the steps of: forming a support member, said support member defining a cavity; forming a rib connected to said support member extending into said cavity; forming an electronic element in stress communicating relationship with said rib; forming a diaphragm connected to said support member and said rib; and forming a boss connected to said rib.
Claim 2
Independent Claim
63 words
A method of forming a pressure transducer, comprising the steps of: forming a support member, said support member defining a cavity; forming a rib connected to said support member extending into said cavity; forming an electronic element in stress communicating relationship with said rib; forming a diaphragm connected to said support member and said rib; and forming a boss connected to said rib.
Claim 3
Dependent Claim
33 words
The method of claim 1, comprising the further steps of: forming a region of passivating oxide material on said rib over the electronic element; and extending said diaphragm over all of said rib.
Claim 4
Dependent Claim
25 words
The method of claim 1, comprising the further step of: forming an overpressure stop region connected to said support member which extends into said cavity.
Claim 5
Independent Claim
179 words
A method of forming a pressure transducer, comprising: forming a first layer having first and second surfaces; forming a first region at said first surface, said first region being of a different conductivity type than said first layer; forming a second layer at said first surface; forming a second region in said second layer, said second region being of a different conductivity type than said second layer, said first and second regions being generally aligned with each other; forming a third layer of sacrificial material over said second layer in a predefined pattern, said second layer being disposed between said first and third layers; forming a polysilicon diaphragm layer over said third layer and over portions of said second layer which are not covered by said third layer; etching said first layer at said second surface to remove a portion of said first layer, said first and second regions and said third layer to provide a cavity between said second layer and said polysilicon diaphragm layer; and forming a piezoresistive component in stress communication with said polysilicon diaphragm layer.
Claim 6
Independent Claim
179 words
A method of forming a pressure transducer, comprising: forming a first layer having first and second surfaces; forming a first region at said first surface, said first region being of a different conductivity type than said first layer; forming a second layer at said first surface; forming a second region in said second layer, said second region being of a different conductivity type than said second layer, said first and second regions being generally aligned with each other; forming a third layer of sacrificial material over said second layer in a predefined pattern, said second layer being disposed between said first and third layers; forming a polysilicon diaphragm layer over said third layer and over portions of said second layer which are not covered by said third layer; etching said first layer at said second surface to remove a portion of said first layer, said first and second regions and said third layer to provide a cavity between said second layer and said polysilicon diaphragm layer; and forming a piezoresistive component in stress communication with said polysilicon diaphragm layer.
Claim 7
Dependent Claim
49 words
The method of claim 4, wherein: said first layer is made of P- type silicon, said first region is a P+ conductivity type material, said second layer is made of N- type silicon, said second region is a highly doped P+ material and said sacrificial material is an oxide.
Claim 8
Dependent Claim
29 words
The method of claim 4, wherein: said first and second regions are shaped to define a rib extending from a peripheral rim as a result of said etching step.
Claim 9
Dependent Claim
35 words
The method of claim 4, wherein: said predefined pattern is selected to provide a direct contact between said second layer and said polysilicon diaphragm layer at a region of said rib displaced from said rim.
Claim 10
Dependent Claim
14 words
The method of claim 7, wherein: said piezoresistive component is formed in said rib.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-07-05 | 1997-01-04 | 1997-07-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-07-05 | 2001-01-04 | 2001-07-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-07-05 | 2005-01-04 | 2005-07-06 | $7700.00 | Window Closed / Lapsed |