US5602043A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Monolithic thermal detector with pyroelectric film and method
Assignee: Texas Instruments Inc
•
Filing: 1995-01-03
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Granted: 1997-02-11
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Expires: 2015-01-03
Abstract
Abstract One or more thin film layers of material may be formed on an integrated circuit substrate and anisotropically etched to produce a monolithic thermal detector. A first layer of material may be placed on the integrated circuit substrate and anisotropically etched to form a plurality of supporting structures for the thermal sensors of the associated focal plane array. The thermal sensors of the focal plane array may be provided by anisotropically etching one or more thin film layers of material formed on the supporting structures. In an exemplary thermal detector, one of the thin film layers preferably includes pyroelectric material such as barium strontium titanate. A layer of thermal insulating material may be disposed between the integrated circuit substrate and the pyroelectric film layer to allow annealing of the pyroelectric film layer without causing damage to the associated integrated circuit substrate. In addition to the layer of insulating material, a heat sink may be disposed on the integrated circuit substrate opposite from the pyroelectric film layer to protect the integrated circuit substrate while annealing the pyroelectric film layer. Alternatively, a thermal isolation structure may be formed between the pyroelectric film layer and its associated supporting structures to allow annealing of the pyroelectric film layer without substantial heating of the underlying circuit substrate.
Inventors
- 👤 Howard R. Beratan
- 👤 Charles M. Hanson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 01:07
CPC Classifications
G; G01; G01J; G01J5/00; G01J5/10; G01J5/34; H; H10; H10F; H10F39/00; H10F39/10; H10F39/12; H10F39/18; H10F39/184; H10F39/1843; H10N; H10N15/00; H10N15/10
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
221 words
A method for fabricating a monolithic thermal detector having a focal plane array of thermal sensors disposed on an integrated circuit substrate comprising the steps of: forming a first layer of electrically conductive material on one surface of the integrated circuit substrate; anisotropically etching the first layer of electrically conductive material to form supporting structures for respective thermal sensors; forming a second layer of thermal insulating material on the one surface of the integrated circuit substrate with the supporting structures disposed therein; forming a third layer of electrically conductive material on the supporting structures and the layer of insulating material; forming a thin film layer of thermal sensitive material on the third layer of electrically conductive material; forming a fourth layer of electrically conductive material on the thin film layer; etching the layer of thermal insulating material, the third and fourth layers of electrically conductive material and the thin film layer of thermal sensitive material to form the plurality of thermal sensors which comprise the focal plane array disposed on the integrated circuit substrate; and applying heat to one side of the thin film layer of thermal sensitive material with the layer of thermal insulating material disposed between the one surface of the integrated circuit substrate and the thin film layer of thermal sensitive material to anneal the thin film layer.
Claim 2
Independent Claim
221 words
A method for fabricating a monolithic thermal detector having a focal plane array of thermal sensors disposed on an integrated circuit substrate comprising the steps of: forming a first layer of electrically conductive material on one surface of the integrated circuit substrate; anisotropically etching the first layer of electrically conductive material to form supporting structures for respective thermal sensors; forming a second layer of thermal insulating material on the one surface of the integrated circuit substrate with the supporting structures disposed therein; forming a third layer of electrically conductive material on the supporting structures and the layer of insulating material; forming a thin film layer of thermal sensitive material on the third layer of electrically conductive material; forming a fourth layer of electrically conductive material on the thin film layer; etching the layer of thermal insulating material, the third and fourth layers of electrically conductive material and the thin film layer of thermal sensitive material to form the plurality of thermal sensors which comprise the focal plane array disposed on the integrated circuit substrate; and applying heat to one side of the thin film layer of thermal sensitive material with the layer of thermal insulating material disposed between the one surface of the integrated circuit substrate and the thin film layer of thermal sensitive material to anneal the thin film layer.
Claim 3
Dependent Claim
17 words
The method of claim 1, wherein the second layer of thermal insulating material is formed from polyimide.
Claim 4
Dependent Claim
44 words
The method of claim 1, wherein the thin film layer is formed from material selected from the group consisting of barium strontium titanate, barium titanate, antimony sulfoiodide, vanadium oxide, lead titanate, lead lanthanum titanate, lead zirconate titanate, lead lanthanum zirconate titanate and amorphous silicon.
Claim 5
Dependent Claim
19 words
The method of claim 1, wherein the step of anisotropically etching is performed using an oxygen-based reactive ion etch.
Claim 6
Dependent Claim
19 words
The method of claim 1, wherein the step of forming the supporting structure is performed using a photolithographic process.
Claim 7
Dependent Claim
29 words
The method of claim 1, further comprising the step of placing a heat sink on the integrated circuit substrate opposite from the one surface of the integrated circuit substrate.
Claim 8
Independent Claim
213 words
A method for fabricating a monolithic thermal detector having a focal plane array of thermal sensors disposed on one surface of an integrated substrate with an array of contact pads for respectively receiving signals from the thermal sensors, comprising the steps of: forming a first layer of electrically conductive material on the one surface of the integrated circuit substrate; anisotropically etching the first layer of electrically conductive material to form supporting structures for the respective thermal sensors with at least one of the supporting structures disposed adjacent to the contact pad for the respective thermal sensor; forming a second layer of insulating material on the one surface of the integrated circuit substrate with the supporting structures disposed therein; forming third layer of electrically conductive material on the supporting structures and the layer of insulating material; forming a thin film layer of pyroelectric material on the third layer of electrically conductive material; forming a fourth layer of electrically conductive material on the thin film layer; etching the layer of insulating material, the third and fourth layers of electrically conductive material and the thin film layer of pyroelectric material to form the thermal sensors which comprise the focal plane array disposed on the integrated circuit substrate; and annealing the thin film layer of pyroelectric material.
Claim 9
Independent Claim
213 words
A method for fabricating a monolithic thermal detector having a focal plane array of thermal sensors disposed on one surface of an integrated substrate with an array of contact pads for respectively receiving signals from the thermal sensors, comprising the steps of: forming a first layer of electrically conductive material on the one surface of the integrated circuit substrate; anisotropically etching the first layer of electrically conductive material to form supporting structures for the respective thermal sensors with at least one of the supporting structures disposed adjacent to the contact pad for the respective thermal sensor; forming a second layer of insulating material on the one surface of the integrated circuit substrate with the supporting structures disposed therein; forming third layer of electrically conductive material on the supporting structures and the layer of insulating material; forming a thin film layer of pyroelectric material on the third layer of electrically conductive material; forming a fourth layer of electrically conductive material on the thin film layer; etching the layer of insulating material, the third and fourth layers of electrically conductive material and the thin film layer of pyroelectric material to form the thermal sensors which comprise the focal plane array disposed on the integrated circuit substrate; and annealing the thin film layer of pyroelectric material.
Claim 10
Dependent Claim
50 words
The method of claim 7, further comprising the steps of: etching the thin film layer of pyroelectric material to form respective thermal isolation structures between the thermal sensors and their associated supporting structures; and annealing the thin film layer of pyroelectric material after the thermal isolation structures have been formed.
Claim 11
Dependent Claim
17 words
The method of claim 7 wherein the second layer of insulating material is formed from silicon dioxide.
Claim 12
Dependent Claim
61 words
The method of claim 7, further comprising the steps of: patterning the film layers formed on the supporting structures and the layer of insulating material to correspond with the desired thermal sensors; and anisotropically etching the film layers and the layer of insulating material to form the thermal sensors which comprise the focal plane array disposed on the integrated circuit substrate.
Claim 13
Dependent Claim
11 words
The method of claim 7, wherein the insulating material is polyimide.
Claim 14
Dependent Claim
20 words
The method of claim 7, wherein the step of anisotropically etching is performed using an magnetically enhanced reactive ion etch.
Claim 15
Dependent Claim
12 words
The method of claim 1, wherein the thin film layer is pyroelectric.
Claim 16
Dependent Claim
31 words
The method of claim 1, further comprising the step of: removing the layer of thermal insulating material to form cavities between said integrated circuit substrate and each of said thermal sensors.
Claim 17
Dependent Claim
30 words
The method of claim 7, further comprising the step of: removing the layer of insulating material to form cavities between said integrated circuit substrate and each of said thermal sensors.
References Cited (Backward Citations)
CA939943A
Cited
US3846820A
Cited
US4018608A
Cited
US4080532A
Cited
US4205227A
Cited
US4143269A
Cited
US4162402A
Cited
US4379232A
Cited
US4142207A
Cited
US4275302A
Cited
US4593456A
Cited
US4594507A
Cited
US4710732A
Cited
US5061049A
Cited
US4615595A
Cited
US4751387A
Cited
US4705361A
Cited
US4956619A
Cited
US5010251A
Cited
US5021663B1
Cited
US5021663A
Cited
US5036197A
Cited
US5051591A
Cited
US5047644A
Cited
US5264326A
Cited
US4994672A
Cited
GB2251952A
Cited
US5118944A
Cited
WO1991016607A1
Cited
US5369280A
Cited
US5083857A
Cited
US5196703A
Cited
US5367167A
Cited
US5288649A
Cited
US5293041A
Cited
US5238530A
Cited
GB2282261A
Cited
US5523564A
Cited
US5426304A
Cited
US5485010A
Cited
US5486698A
Cited
US5424544A
Cited
US5457318A
Cited
US5512748A
Cited
US5521104A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-02-11 | 2000-08-12 | 2001-02-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-02-11 | 2004-08-12 | 2005-02-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-02-11 | 2008-08-12 | 2009-02-11 | $7700.00 | Window Closed / Lapsed |