US5503285A
Expired / Lapsed
US
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Method for forming an electrostatically force balanced silicon accelerometer
Assignee: Northrop Grumman Guidance and Electronics Co Inc
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Filing: 1993-07-26
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Granted: 1996-04-02
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Expires: 2013-07-26
Abstract
Abstract An accelerometer is fabricated by forming a proofmass and at least one associated hinge in a silicon substrate by ion implantation and the formation of an oxide support layer below the proofmass, subsequently integrally bonding two complementary proofmass and substrate structures together, and then removing the oxide support layer to leave the proofmass supported by the hinge within the body of silicon material. The proofmass may be electrically connected to a lead extending through an etched recess in one of the substrates; and the proofmass may be electrically isolated or separated from the substrates by an oxide layer and by a change in conductivity type of the semiconductor material where the hinge is structurally mounted to the substrates.
Inventors
- 👤 Keith O. Warren
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 14:21
CPC Classifications
G; G01; G01P; G01P15/00; G01P15/02; G01P15/08; G01P15/0802; G01P15/125; G01P15/13; G01P15/131; G01P2015/0805; G01P2015/0822; G01P2015/0825; G01P2015/0828
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
79 words
A method for forming a solid state accelerometer comprising the steps of: forming a proofmass in a substrate; forming a support layer in the substrate between the proofmass and the substrate; forming at least one hinge selectively attaching the proofmass to the substrate; bonding two substantially complementary proofmasses and associated substrate structures together, with at least one of said structures including said hinge; and selectively removing the support layer located in between the proofmass structures and the surrounding substrate.
Claim 2
Independent Claim
79 words
A method for forming a solid state accelerometer comprising the steps of: forming a proofmass in a substrate; forming a support layer in the substrate between the proofmass and the substrate; forming at least one hinge selectively attaching the proofmass to the substrate; bonding two substantially complementary proofmasses and associated substrate structures together, with at least one of said structures including said hinge; and selectively removing the support layer located in between the proofmass structures and the surrounding substrate.
Claim 3
Dependent Claim
35 words
The method of claim 1 in which said support layer is formed of an oxide layer and further comprising the step of ion implanting the oxide into the substrate to form a buried oxide layer.
Claim 4
Dependent Claim
35 words
The method of claim 1 in which the two complementary proofmasses and substrate structures are formed on a single wafer and further comprising the step of cutting the wafer to separate the two complementary structures.
Claim 5
Dependent Claim
52 words
The method as described in claim 1 in which the hinge is formed by a plurality of tabs extending between the proofmass and the surrounding substrate and further comprising the step of selectively removing portions of the hinge to create a plurality of tabs extending between the proofmass and the surrounding substrate.
Claim 6
Dependent Claim
32 words
A method as defined in claim 1 wherein both of the two complementary proofmasses and substrate structures have hinges and wherein these two hinges are bonded together to form a single hinge.
Claim 7
Dependent Claim
23 words
A method as defined in claim 1 wherein only one of said two complementary proofmasses and substrate structures is formed with a hinge.
Claim 8
Dependent Claim
30 words
A method as defined in claim 1 wherein said support layer is etched away to free said proofmass so that it is supported from the substrate only by said hinge.
Claim 9
Dependent Claim
18 words
A method as defined in claim 1 wherein said method includes electrically connecting a lead to the proofmass.
Claim 10
Dependent Claim
54 words
A method as defined in claim 1 wherein said method includes the steps of electrically separating or isolating said proofmass from the substrates by changing the conductivity type of the semiconductor material where the hinge is physically mounted to the substrate, and by providing an insulating oxide layer to complete the isolation or separation.
Claim 11
Dependent Claim
39 words
The method of claim 1, wherein the step of forming a support layer further comprises the steps of forming a first oxide layer between the proofmass and the substrate; and providing an associated substrate having a second oxide layer.
Claim 12
Dependent Claim
47 words
The method of claim 10, wherein the step of forming at least one hinge further comprises the steps of disposing a nitride pattern of varying thicknesses on the proofmass; disposing a resist pattern having trenches on the second oxide layer; and etching the proofmass and associated substrate.
Claim 13
Dependent Claim
13 words
The method of claim 11, wherein the first oxide layer includes phospho-silicate glass.
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) | 1999-04-02 | 1999-10-02 | 2000-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-04-02 | 2003-10-02 | 2004-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-04-02 | 2007-10-02 | 2008-04-02 | $7700.00 | Window Closed / Lapsed |