EP0400939A2
Expired / Lapsed
EP
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Semiconductor sensor with vibrating element
Assignee: Mobrey Group Ltd
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Filing: 1990-05-29
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Granted: —
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Expires: 2010-05-29
Abstract
Abstract An electromechanical sensor is provided which comprises: a first silicon wafer (22) which defines a resonant element (26); wherein the resonant element is doped with approximately the same impurity concentration as a background dopant concentration of the first wafer; and a second single crystal wafer (28) which defines a device for coupling mechanical stress from the second wafer to the resonant element; wherein the first and second wafers are fusion bonded together.
Inventors
- 👤 Phillip W. Barth
- 👤 Kurt E. Petersen
- 👤 Joseph R. Mallon
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 14:46
CPC Classifications
G; G01; G01L; G01L9/00; G01L9/0001; G01L9/0008; G01L9/0019
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
54 words
An electromechanical sensor comprising: a first single crystal silicon wafer which defines means for vibrating; wherein said means for vibrating is doped with less than approximately 7.0x10¹⁹ dopant atoms per cubic centimeter; and a second single crystal silicon wafer; and means for coupling mechanical stress from said second wafer to said means for vibrating.
Claim 2
Dependent Claim
54 words
An electromechanical sensor comprising: a first single crystal silicon wafer which defines means for vibrating; wherein said means for vibrating is doped with less than approximately 7.0x10¹⁹ dopant atoms per cubic centimeter; and a second single crystal silicon wafer; and means for coupling mechanical stress from said second wafer to said means for vibrating.
Claim 3
Dependent Claim
15 words
The sensor of claim 1, wherein said first and second wafers are fusion bonded together.
Claim 4
Dependent Claim
46 words
An electromechanical sensor comprising: a first single crystal silicon wafer which defines means for vibrating; and a second single crystal wafer and means for coupling mechanical stress from said second wafer to said means for vibrating; wherein said first and second wafers are fusion bonded together.
Claim 5
Dependent Claim
46 words
An electromechanical sensor comprising: a first single crystal silicon wafer which defines means for vibrating; and a second single crystal wafer and means for coupling mechanical stress from said second wafer to said means for vibrating; wherein said first and second wafers are fusion bonded together.
Claim 6
Dependent Claim
22 words
The sensor of claim 3, wherein said means for vibrating is doped with less than approximately 7.0x10¹⁹ dopant atoms per cubic centimeter.
Claim 7
Dependent Claim
18 words
The sensor of any one of the preceding claims, wherein said means for vibrating includes a vibratable beam.
Claim 8
Dependent Claim
27 words
The sensor of any one of claims 1 to 4, wherein said means for vibrating comprises an elongated beam having at least one piezoresistive element formed therein.
Claim 9
Dependent Claim
34 words
The sensor of claim 5 or claim 6, wherein said first wafer is a <100> oriented wafer, and said beam has a longitudinal axis substantially aligned along a (110) direction in said first wafer.
Claim 10
Dependent Claim
34 words
The sensor of claim 5 or claim 6, wherein said first wafer is a <100> oriented wafer, and said beam has a longitudinal axis substantially aligned along a (100) direction in said first wafer.
Claim 11
Dependent Claim
79 words
An electromechanical sensor comprising: a first single crystal silicon wafer which defines means for vibrating in the form of a vibratable beam; at least one piezoresistive element formed in said vibratable beam; a second single crystal silicon wafer which defines a first shallow recessed region; means for coupling mechanical stress from said second wafer to said vibratable beam; wherein said first and second wafers are laminated together such that said vibratable beam is disposed opposite said shallow recessed region.
Claim 12
Dependent Claim
79 words
An electromechanical sensor comprising: a first single crystal silicon wafer which defines means for vibrating in the form of a vibratable beam; at least one piezoresistive element formed in said vibratable beam; a second single crystal silicon wafer which defines a first shallow recessed region; means for coupling mechanical stress from said second wafer to said vibratable beam; wherein said first and second wafers are laminated together such that said vibratable beam is disposed opposite said shallow recessed region.
Claim 13
Dependent Claim
15 words
The sensor of claim 9, further comprising an electrode formed in the shallow recessed region.
Claim 14
Dependent Claim
38 words
The sensor of claim 9 or claim 10, wherein said first wafer includes <100> oriented single crystal silicon, and said vibratable beam has a longitudinal axis that is substantially aligned along a (110) direction in said first wafer.
Claim 15
Dependent Claim
36 words
The sensor of claim 9 or claim 10, wherein said first wafer includes <110> oriented single crystal silicon, and said vibratable beam has a longitudinal axis substantially aligned along a (110) direction in said first wafer.
Claim 16
Dependent Claim
51 words
The sensor of claim 9 or claim 10, wherein said first wafer includes <100> oriented single crystal silicon, at least two piezoresistive elements are formed in said vibratable beam, and an axis passing through said at least two piezoresistive elements is substantially aligned along a (100) direction in said first wafer.
Claim 17
Dependent Claim
51 words
The sensor of claim 9 or claim 10, wherein said first wafer includes <110> oriented single crystal silicon, at least two piezoresistive elements are formed in said vibratable beam, and an axis passing through said at least two piezoresistive elements is substantially aligned along a (100) direction in said first wafer.
Claim 18
Dependent Claim
29 words
The sensor of any one of claims 9 to 14, and further comprising means for substantially electrically isolating said at least one piezoresistive element from said means for measuring.
Claim 19
Dependent Claim
20 words
The sensor of any one of claims 9 to 15, wherein said first and second wafers are fusion bonded together.
Claim 20
Dependent Claim
50 words
The sensor of any one of claims 9 to 15, wherein said first and second wafers are fusion bonded together, and an unbonded surface of said first wafer is substantially planar and said vibratable beam includes a surface that is substantially coplanar with said unbonded surface of said first wafer.
Claim 21
Dependent Claim
24 words
The sensor of any one of claims 9 to 17, and further comprising a plurality of piezoresistive elements coupled in a Wheatstone Bridge circuit.
Claim 22
Dependent Claim
32 words
The sensor of any preceding claim, wherein a resonant frequency of said means for vibrating varies in response to mechanical stress coupled to said means for vibrating by said means for coupling.
Claim 23
Dependent Claim
19 words
The sensor of any preceding claim, and further comprising means for measuring resonant frequency of said means for vibrating.
Claim 24
Dependent Claim
19 words
The sensor of any preceding claim, and further comprising means for stimulating resonant vibration by said means for vibrating.
Claim 25
Dependent Claim
14 words
The sensor of any preceding claim, wherein said means for coupling comprises a diaphragm.
Claim 26
Dependent Claim
24 words
The sensor of any preceding claim, wherein said means for coupling comprises a diaphragm and said means for vibrating is formed on said diaphragm.
Claim 27
Dependent Claim
22 words
The sensor of any preceding claim, wherein said means for coupling comprises a seismic mass secured to said first and second wafers.
Claim 28
Dependent Claim
28 words
The sensor of any preceding claim, wherein said means for vibrating is doped with substantially the same impurity concentration as a background doping concentration of said first wafer.
Claim 29
Dependent Claim
20 words
The sensor of any one of claims 1, 3 and 9, wherein said second wafer defines said means for coupling.
References Cited (Backward Citations)
No citation records indexed.
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