US4953387A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Ultrathin-film gas detector
Assignee: MICHIGAN ANN ARBOR MI 48109, University of, Regents of
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Filing: 1989-07-31
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Granted: 1990-09-04
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Expires: 2009-07-31
Abstract
Abstract A device for detecting a gaseous species including (i) a silicon substrate having two major surfaces and comprising a dielectric window region (ii) a heater situated on the dielectric window region on one major surface; and (iii) a conductivity cell electrode thin metal transducing film assembly situated on the dielectric window region on the other major surface is disclosed. The thin transducing film contacts the conductivity cell electrode.
Inventors
- 👤 Christy L. Johnson
- 👤 Johannes Schwank
- 👤 Kensall D. Wise
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:20
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/02; G01N27/04; G01N27/12; G01N27/128
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
97 words
A device for detecting a gaseous species, comprising: (i) a substrate having two opposed major surfaces and including a dielectric window region; (ii) heater means situated on said dielectric window region on one of said opposed surfaces; and (iii) a conductivity cell electrode means/thin transducing metal film assembly situated on said dielectric window region on the other of said opposed surfaces; wherein: said thin transducing metal film contacts said conductivity cell electrode means; said heater means heats said thin transducing film; and said conductivity cell electrode means senses the conductivity and capacitance of said thin transducing film.
Claim 2
Independent Claim
97 words
A device for detecting a gaseous species, comprising: (i) a substrate having two opposed major surfaces and including a dielectric window region; (ii) heater means situated on said dielectric window region on one of said opposed surfaces; and (iii) a conductivity cell electrode means/thin transducing metal film assembly situated on said dielectric window region on the other of said opposed surfaces; wherein: said thin transducing metal film contacts said conductivity cell electrode means; said heater means heats said thin transducing film; and said conductivity cell electrode means senses the conductivity and capacitance of said thin transducing film.
Claim 3
Dependent Claim
44 words
The device of claim 1, wherein said metal film is at least one member selected from the group consisting of platinum, palladium, ruthenium, nickel, copper, rhodium, molybdenum, iridium, iron, cobalt, titanium, vanadium, tantalum, tungsten, chromium, manganese, gold, aluminum, tin, magnesium, osmium, zinc and silver.
Claim 4
Dependent Claim
20 words
The device of claim 1, wherein said thin transducing metal film has a thickness of 0.5 nm to 25 nm.
Claim 5
Dependent Claim
21 words
The device of claim 1, wherein said thin transducing metal film has a thickness of from 5 nm to 10 nm.
Claim 6
Dependent Claim
22 words
The device of claim 1, wherein said thin transducing metal film has a resistance of from 10 ohms to 10 7 ohms.
Claim 7
Dependent Claim
23 words
The device of claim 1, wherein said thin transducing metal film has a resistance of from 10 3 ohms to 10 4 ohms.
Claim 8
Dependent Claim
14 words
The device of claim 1, wherein said conductivity cell electrode means are chrome/gold electrodes.
Claim 9
Dependent Claim
23 words
The device of claim 1, wherein said conductivity cell electrode means are made of a refractory material such as Ir, Ta or Ti.
Claim 10
Dependent Claim
14 words
The device of claim 1, wherein said heater means is a polysilicon heater means.
Claim 11
Dependent Claim
15 words
The device of claim 1, wherein said heater means is a boron-doped silicon heater means.
Claim 12
Dependent Claim
22 words
The device of claim 1, wherein said substrate is a laminate comprising a silicon nitride layer sandwiched between two silicon oxide layers.
Claim 13
Dependent Claim
25 words
The device of claim 11, wherein the substrate has a thickness in which the total silicon oxide to silicon nitride ratio is at least 1:1.
Claim 14
Dependent Claim
13 words
The device of claim 12, wherein said ratio is from 2.5:1 to 6:1.
Claim 15
Independent Claim
117 words
A device for detecting a gaseous species, comprising: (i) a substrate having two opposed major surfaces and including a dielectric window region; (ii) a heater means situated on said dielectric window region on one of said opposed surfaces; (iii) a first set of conductivity cell electrode means/thin transducing metal film/second set of conductivity cell electrode means assembly situated on said dielectric window region on the other of said opposed surfaces; wherein: said second-thin transducing metal film contacts said first and said second set of conductivity cell electrode means; said heater means heats said thin transducing metal film; and said first and second conductivity cell electrode means sense the conductivity and capacitance of said thin transducing metal film.
Claim 16
Independent Claim
117 words
A device for detecting a gaseous species, comprising: (i) a substrate having two opposed major surfaces and including a dielectric window region; (ii) a heater means situated on said dielectric window region on one of said opposed surfaces; (iii) a first set of conductivity cell electrode means/thin transducing metal film/second set of conductivity cell electrode means assembly situated on said dielectric window region on the other of said opposed surfaces; wherein: said second-thin transducing metal film contacts said first and said second set of conductivity cell electrode means; said heater means heats said thin transducing metal film; and said first and second conductivity cell electrode means sense the conductivity and capacitance of said thin transducing metal film.
Claim 17
Dependent Claim
20 words
The device of claim 14, wherein said thin transducing metal film has a thickness of 0.5 nm to 25 nm.
Claim 18
Dependent Claim
21 words
The device of claim 14, wherein said thin transducing metal film has a thickness of from 5 nm to 10 nm.
Claim 19
Dependent Claim
22 words
The device of claim 14, wherein said thin transducing metal film has a resistance of from 10 ohms to 10 7 ohms.
Claim 20
Dependent Claim
23 words
The device of claim 14, wherein said thin transducing metal film has a resistance of from 10 3 ohms to 10 4 ohms.
Claim 21
Dependent Claim
14 words
The device of claim 14, wherein said conductivity cell electrode means are chrome/gold electrodes.
Claim 22
Dependent Claim
23 words
The device of claim 14, wherein said conductivity cell electrode means are made of a refractory material such as Ir, Ta or Ti.
Claim 23
Dependent Claim
14 words
The device of claim 14, wherein said heater means is a polysilicon heater means.
Claim 24
Dependent Claim
15 words
The device of claim 14, wherein said heater means is a boron-doped silicon heater means.
Claim 25
Dependent Claim
22 words
The device of claim 14, wherein said substrate is a laminate comprising a silicon nitride layer sandwiched between two silicon oxide layers.
Claim 26
Dependent Claim
25 words
The device of claim 23, wherein the substrate has a thickness in which the total silicon oxide to silicon nitride ration is at least 1:1.
Claim 27
Dependent Claim
13 words
The device of claim 24, wherein said ratio is from 2.5:1 to 6:1.
Claim 28
Dependent Claim
114 words
A multi-element gas analyzer chip, comprising: (i) a substrate having two opposed major surfaces and including a plurality of dielectric window regions; (ii) heater means situated on each of said dielectric window region on one of said opposed surfaces; and (iii) a set of conductivity cell electrode means/thin transducing metal film assembly situated on each of said dielectric window region on the other of said opposed surfaces; wherein: each thin transducing metal film contacts each corresponding set of conductivity cell electrode means; each of said heater means independently heats each corresponding thin transducing metal film; each of said conductivity cell electrode means senses the conductivity and capacitance of said corresponding transducing thin metal film.
Claim 29
Dependent Claim
114 words
A multi-element gas analyzer chip, comprising: (i) a substrate having two opposed major surfaces and including a plurality of dielectric window regions; (ii) heater means situated on each of said dielectric window region on one of said opposed surfaces; and (iii) a set of conductivity cell electrode means/thin transducing metal film assembly situated on each of said dielectric window region on the other of said opposed surfaces; wherein: each thin transducing metal film contacts each corresponding set of conductivity cell electrode means; each of said heater means independently heats each corresponding thin transducing metal film; each of said conductivity cell electrode means senses the conductivity and capacitance of said corresponding transducing thin metal film.
Claim 30
Dependent Claim
119 words
A multi-element gas analyzer chip, comprising: (i) a substrate having two opposed major surfaces and including a plurality of dielectric window regions; (ii) heater means situated on each of said dielectric window region on one of said opposed surfaces; and (iii) first set of conductivity cell electrode means/thin transducing metal film/second set of conductivity cell electrode means assembly situated on each of said dielectric window region on the other of said opposed surfaces; wherein: each thin transducing film contacts each corresponding set of conductivity cell electrode means; each of said heater means independently heats each corresponding thin transducing metal film; each of said conductivity cell electrode means senses the conductivity and capacitance of said corresponding transducing thin metal film.
Claim 31
Dependent Claim
119 words
A multi-element gas analyzer chip, comprising: (i) a substrate having two opposed major surfaces and including a plurality of dielectric window regions; (ii) heater means situated on each of said dielectric window region on one of said opposed surfaces; and (iii) first set of conductivity cell electrode means/thin transducing metal film/second set of conductivity cell electrode means assembly situated on each of said dielectric window region on the other of said opposed surfaces; wherein: each thin transducing film contacts each corresponding set of conductivity cell electrode means; each of said heater means independently heats each corresponding thin transducing metal film; each of said conductivity cell electrode means senses the conductivity and capacitance of said corresponding transducing thin metal film.
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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) | 1993-09-03 | 1994-03-05 | 1994-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-09-03 | 1998-03-05 | 1998-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-09-03 | 2002-03-05 | 2002-09-04 | $7700.00 | Window Closed / Lapsed |