US5464966A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Micro-hotplate devices and methods for their fabrication
Assignee: National Institute of Standards and Technology
•
Filing: 1992-10-26
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Granted: 1995-11-07
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Expires: 2012-10-26
Abstract
Abstract A design and fabrication methodology, for silicon micromachined micro-hotplates which are manufactured using commercial CMOS foundries techniques with additional post-fabrication processing. The micro-hotplates are adaptable for a host of applications. The methodology for the fabrication of the micro-hotplates is based on commercial CMOS compatible micromachining techniques. The novel aspects of the micro-hotplates are in the design, choice and layout of the materials layers, and the applications for the devices. The micro-hotplates have advantages over other similar devices in the manufacture by a standard CMOS process which include low-cost and easy integration of VLSI circuits for drive, communication, and control. The micro-hotplates can be easily incorporated into arrays of micro-hotplates each with individualized circuits for control and sensing for independent operation.
Inventors
- 👤 Michael Gaitan
- 👤 John S. Suehle
- 👤 Stephen Semancik
- 👤 Richard E. Cavicchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 18:55
CPC Classifications
B; B01; B01L; B01L7/00; G; G01; G01N; G01N27/00; G01N27/02; G01N27/04; G01N27/14; G01N27/18; H; H05; H05B; H05B3/00; H05B3/10; H05B3/12; H05B3/14; H05B3/148; B01L2200/00; B01L2200/14; B01L2200/143; B01L2200/147; B01L2300/00; B01L2300/18; B01L2300/1805; B01L2300/1827; B01L2300/1883; H05B2203/00; H05B2203/002; H05B2203/003; H05B2213/00; H05B2213/07
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
81 words
A micro-hotplate device which comprises: a support substrate; a microbridge structure formed on said support substrate, said microbridge structure having a suspended portion; a heating element formed directly on said microbridge structure so as to be thermally isolated from said support substrate; a layer of electrically insulating material formed directly on said heating element; and a conductive heat distribution plate formed directly on said layer of electrically insulating material, said conductive heat distribution plate being centrally located over said microbridge structure.
Claim 2
Dependent Claim
81 words
A micro-hotplate device which comprises: a support substrate; a microbridge structure formed on said support substrate, said microbridge structure having a suspended portion; a heating element formed directly on said microbridge structure so as to be thermally isolated from said support substrate; a layer of electrically insulating material formed directly on said heating element; and a conductive heat distribution plate formed directly on said layer of electrically insulating material, said conductive heat distribution plate being centrally located over said microbridge structure.
Claim 3
Dependent Claim
18 words
A micro-hotplate according to claim 1, wherein said conductive heat distribution plate includes four leads for sensing temperature.
Claim 4
Dependent Claim
17 words
A micro-hotplate according to claim 1, wherein the microbridge structure comprises a layer of electrical insulation material.
Claim 5
Dependent Claim
27 words
A micro-hotplate according to claim 3, wherein a central portion of the microbridge structure is suspended over an etch pit which is formed in the substrate support.
Claim 6
Dependent Claim
16 words
A micro-hotplate according to claim 4, wherein said etch pit is formed with a closed bottom.
Claim 7
Dependent Claim
25 words
A micro-hotplate according to claim 3, wherein a central portion of the microbridge structure is suspended over an etch pit which has a closed bottom.
Claim 8
Dependent Claim
38 words
A micro-hotplate according to claim 1, further comprising a layer of an electrical insulating material formed on a side of the conductive heat distribution plate which side is opposite to a side thereof which faces said heating element.
Claim 9
Dependent Claim
23 words
A micro-hotplate according to claim 7, further comprising a plurality of contact pads which are formed on said layer of electrical insulating material.
Claim 10
Dependent Claim
42 words
A micro-hotplate according to claim 8, wherein said contact pads are covered with another layer of an electrical insulating material which includes through holes that allow portions of the contact pads to be exposed through said another layer of electrical insulating material.
Claim 11
Dependent Claim
13 words
A micro-hotplate according to claim 8, wherein said contact pads include electrical leads.
Claim 12
Dependent Claim
12 words
A micro-hotplate according to claim 8, wherein said contact pads comprise aluminum.
Claim 13
Dependent Claim
22 words
A micro-hotplate according to claim 1, wherein said micro-hotplate has a size of between about 2.5×10 3 and 6.4×10 5 square microns.
Claim 14
Dependent Claim
12 words
A micro-hotplate according to claim 1, wherein said support substrate comprises silicon.
Claim 15
Dependent Claim
17 words
A micro-hotplate according to claim 13, wherein said silicon support substrate comprises a silicon wafer or chip.
Claim 16
Dependent Claim
12 words
A micro-hotplate according to claim 1, wherein said heating element comprises polysilicon.
Claim 17
Dependent Claim
14 words
A micro-hotplate according to claim 1, wherein said conductive heat distribution plate comprises aluminum.
Claim 18
Dependent Claim
95 words
An array of micro-hotplate devices which comprises: a support substrate; a plurality of microbridge structures formed on said support substrate, each of said plurality of microbridge structures having a suspended portion; individual heating elements formed directly on each of said plurality of microbridge structures so as to be thermally isolated from said support substrate; a layer of electrically insulating material formed directly on each of said heating elements; and individual conductive heat distribution plates formed directly on said layer of electrically insulating material above each heating element and located centrally over an underlying microbridge structure.
Claim 19
Dependent Claim
95 words
An array of micro-hotplate devices which comprises: a support substrate; a plurality of microbridge structures formed on said support substrate, each of said plurality of microbridge structures having a suspended portion; individual heating elements formed directly on each of said plurality of microbridge structures so as to be thermally isolated from said support substrate; a layer of electrically insulating material formed directly on each of said heating elements; and individual conductive heat distribution plates formed directly on said layer of electrically insulating material above each heating element and located centrally over an underlying microbridge structure.
Claim 20
Independent Claim
138 words
A method of making a micro-hotplate device which comprises: providing a support substrate having a first layer of an insulating material; designing said first layer of insulating material into opening portions and a bridge portion; removing the first layer of insulating material from said opening portions; forming a heating element directly on said bridge portion; forming a second layer of insulating material directly on said heating element; forming a conductive heat distribution plate directly on said second layer of insulating material, said conductive heat distribution plate being located centrally over said microbridge structure; forming a third layer of insulating material on said conductive heat distribution plate; and thereafter, etching out a portion of said support substrate beneath said bridge portion through said opening portions so as to suspend and thermally isolate said bridge portion from said support substrate.
Claim 21
Independent Claim
138 words
A method of making a micro-hotplate device which comprises: providing a support substrate having a first layer of an insulating material; designing said first layer of insulating material into opening portions and a bridge portion; removing the first layer of insulating material from said opening portions; forming a heating element directly on said bridge portion; forming a second layer of insulating material directly on said heating element; forming a conductive heat distribution plate directly on said second layer of insulating material, said conductive heat distribution plate being located centrally over said microbridge structure; forming a third layer of insulating material on said conductive heat distribution plate; and thereafter, etching out a portion of said support substrate beneath said bridge portion through said opening portions so as to suspend and thermally isolate said bridge portion from said support substrate.
Claim 22
Dependent Claim
25 words
A method of making a micro-hotplate device according to claim 18, further comprising forming four leads which are connected to said conductive heat distribution plate.
Claim 23
Dependent Claim
64 words
A method of making a micro-hotplate device according to claim 18, further comprising, prior to said etching step, forming a plurality of contact pads on said third layer of insulating material; and forming a fourth layer of insulating material on said contact pads, with through holes therein which allow portions of said contact pads to be exposed through said fourth layer of insulating material.
Claim 24
Dependent Claim
185 words
A micro-hotplate device which comprises: a support substrate; a microbridge structure formed on said support substrate; a heating element formed on said microbridge structure so as to be thermally isolated from said support substrate; and a conductive heat distribution plate formed above said heating element, said micro-hotplate made by: providing a first layer of an insulating material on said support substrate; dividing said first layer of insulating material into opening portions and a bridge portion; removing the first layer of insulating material from said opening portions; forming said heating element directly on said bridge portion of said first layer of insulating material; forming a second layer of insulating material directly on said heating element; forming said conductive heat distribution plate directly on said second layer of insulating material, said conductive heat distribution plate being located centrally over said bridge portion; forming a third layer of insulating material on said conductive heat distribution plate; and thereafter, etching out a portion of said support substrate beneath said bridge portion through said opening portions so as to suspend and thermally isolate said bridge portion from said support substrate.
Claim 25
Dependent Claim
185 words
A micro-hotplate device which comprises: a support substrate; a microbridge structure formed on said support substrate; a heating element formed on said microbridge structure so as to be thermally isolated from said support substrate; and a conductive heat distribution plate formed above said heating element, said micro-hotplate made by: providing a first layer of an insulating material on said support substrate; dividing said first layer of insulating material into opening portions and a bridge portion; removing the first layer of insulating material from said opening portions; forming said heating element directly on said bridge portion of said first layer of insulating material; forming a second layer of insulating material directly on said heating element; forming said conductive heat distribution plate directly on said second layer of insulating material, said conductive heat distribution plate being located centrally over said bridge portion; forming a third layer of insulating material on said conductive heat distribution plate; and thereafter, etching out a portion of said support substrate beneath said bridge portion through said opening portions so as to suspend and thermally isolate said bridge portion from said support substrate.
Claim 26
Dependent Claim
18 words
A micro-hotplate according to claim 21, wherein said conductive heat distribution plate includes four leads for sensing temperature.
Claim 27
Dependent Claim
23 words
A micro-hotplate according to claim 21, further comprising a plurality of contact pads which are formed on said third layer of insulating material.
Claim 28
Dependent Claim
42 words
A micro-hotplate according to claim 23, wherein said contact pads are covered with another layer of an electrical insulating material which includes through holes that allow portions of the contact pads to be exposed through said another layer of electrical insulating material.
Claim 29
Dependent Claim
13 words
A micro-hotplate according to claim 23, wherein said contact pads include electrical leads.
Claim 30
Dependent Claim
12 words
A micro-hotplate according to claim 23, wherein said contact pads comprise aluminum.
Claim 31
Dependent Claim
22 words
A micro-hotplate according to claim 21, wherein said micro-hotplate has a size of between about 2.5×10 3 and 6.4×10 5 square microns.
Claim 32
Dependent Claim
12 words
A micro-hotplate according to claim 21, wherein said support substrate comprises silicon.
Claim 33
Dependent Claim
17 words
A micro-hotplate according to claim 28, wherein said silicon support substrate comprises a silicon wafer or chip.
Claim 34
Dependent Claim
12 words
A micro-hotplate according to claim 21, wherein said heating element comprises polysilicon.
Claim 35
Dependent Claim
14 words
A micro-hotplate according to claim 21, wherein said conductive heat distribution plate comprises aluminum.
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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) | 1998-11-06 | 1999-05-08 | 1999-11-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-11-06 | 2003-05-08 | 2003-11-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-11-06 | 2007-05-08 | 2007-11-07 | $7700.00 | Window Closed / Lapsed |