US5260225A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Integrated infrared sensitive bolometers
Assignee: Honeywell Inc
•
Filing: 1992-11-09
•
Granted: 1993-11-09
•
Expires: 2012-11-09
Abstract
Abstract A method for fabricating an integrated infrared sensitive bolometer having a polycrystalline element whereby an oxide region deposited on silicon nitride covered with a first polysilicon layer which is etched to provide a location for a bolometer element. A second polysilicon layer is deposited and doped to achieve a desired temperature coefficient of resistivity of 1 to 2%/°C. The second polysilicon layer forms an IR sensitive element over the oxide region. Openings are etched in the IR sensitive element to permit an etchant to remove the oxide region resulting in the sensitive element being suspended over a cavity.
Inventors
- 👤 Michael S. Liu
- 👤 Jeffrey S. Haviland
- 👤 Cheisan J. Yue
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 04:58
CPC Classifications
G; G01; G01J; G01J5/00; G01J5/10; G01J5/20; H; H10; H10F; H10F71/00; H10F71/121; H10F77/00; H10F77/10; H10F77/16; H10F77/162; H10F77/164; H10F77/1642; Y; Y02; Y02E; Y02E10/00; Y02E10/50; Y02E10/546; Y02E10/547; Y02P; Y02P70/00; Y02P70/50
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
133 words
A method of fabricating an infrared sensitive bolometer having an infrared sensitive element, comprising: providing a semiconductor substrate having a first insulating layer; depositing an oxide layer on said first insulating layer; masking and etching said oxide layer to form a remaining oxide region; depositing a first layer of polysilicon; masking and etching said first layer of polysilicon at said remaining oxide region; depositing a second layer of polysilicon; implanting ions into said second layer of polysilicon to achieve a predetermined temperature coefficient of resistance (TCR); masking and etching said second layer of polysilicon to define at least one opening in said infrared sensitive element; applying etchant through said at least one opening to remove said remaining oxide region and to form a cavity with said infrared sensitive element suspended over said cavity.
Claim 2
Independent Claim
133 words
A method of fabricating an infrared sensitive bolometer having an infrared sensitive element, comprising: providing a semiconductor substrate having a first insulating layer; depositing an oxide layer on said first insulating layer; masking and etching said oxide layer to form a remaining oxide region; depositing a first layer of polysilicon; masking and etching said first layer of polysilicon at said remaining oxide region; depositing a second layer of polysilicon; implanting ions into said second layer of polysilicon to achieve a predetermined temperature coefficient of resistance (TCR); masking and etching said second layer of polysilicon to define at least one opening in said infrared sensitive element; applying etchant through said at least one opening to remove said remaining oxide region and to form a cavity with said infrared sensitive element suspended over said cavity.
Claim 3
Dependent Claim
32 words
The method of claim 1 wherein said step of implanting ions into said second layer of polysilicon includes implanting ions of an element selected from the group including arsenic, phosphorous or boron.
Claim 4
Dependent Claim
30 words
The method of claim 2 wherein said step of implanting ions into said second layer of polysilicon includes implanting arsenic ions to achieve a TCR of about 1 to 2%/°C.
Claim 5
Dependent Claim
18 words
The method of claim 3 wherein said arsenic ions are implanted at an energy of about 60 KeV.
Claim 6
Independent Claim
120 words
A method of fabricating a bolometer having an infrared sensitive element comprising: providing a semiconductor substrate; depositing an oxide layer on said semiconductor substrate; selectively removing a portion of said oxide layer to form a remaining oxide region; depositing a first layer of polysilicon; selectively removing said first layer of polysilicon at said remaining oxide region; depositing a second layer of polysilicon; implanting ions onto said second layer of polysilicon to achieve a predetermined temperature coefficient of resistance (TCR); defining at least one opening in said infrared sensitive element; applying etchant through said at least one opening to remove a substantial portion of said remaining oxide region to form a cavity with said infrared sensitive element suspended over said cavity.
Claim 7
Independent Claim
120 words
A method of fabricating a bolometer having an infrared sensitive element comprising: providing a semiconductor substrate; depositing an oxide layer on said semiconductor substrate; selectively removing a portion of said oxide layer to form a remaining oxide region; depositing a first layer of polysilicon; selectively removing said first layer of polysilicon at said remaining oxide region; depositing a second layer of polysilicon; implanting ions onto said second layer of polysilicon to achieve a predetermined temperature coefficient of resistance (TCR); defining at least one opening in said infrared sensitive element; applying etchant through said at least one opening to remove a substantial portion of said remaining oxide region to form a cavity with said infrared sensitive element suspended over said cavity.
Claim 8
Dependent Claim
32 words
The method of claim 5 wherein said step of implanting ions into said second layer of polysilicon includes implanting ions of an element selected from the group including arsenic, phosphorous or boron.
Claim 9
Dependent Claim
35 words
The method of claim 5 wherein said step of implanting ions into said second layer of polysilicon includes implanting ions to achieve a TCR of between about 1% per °C. and about 7% per °C.
Claim 10
Dependent Claim
30 words
The method of claim 6 wherein said step of implanting ions into said second layer of polysilicon includes implanting arsenic ions to achieve a TCR of about 1 to 2%/°C.
Claim 11
Dependent Claim
30 words
The method of claim 7 wherein said step of implanting ions into said second layer of polysilicon includes implanting arsenic ions to achieve a TCR of about 1 to 2%/°C.
Claim 12
Dependent Claim
18 words
The method of claim 9 wherein said arsenic ions are implanted at an energy of about 60 KeV.
References Cited (Backward Citations)
US4574263A
Cited
US4570329A
Cited
US4665610A
Cited
US4853669A
Cited
US4766666A
Cited
JPS62142372A
Cited
US4965212A
Cited
US4948741A
Cited
US4724356A
Cited
US4922116A
Cited
US5010251A
Cited
US5021663A
Cited
US5021663B1
Cited
US5059543A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-11-08 | 1997-05-10 | 1997-11-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-11-08 | 2001-05-10 | 2001-11-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-11-08 | 2005-05-10 | 2005-11-09 | $7700.00 | Window Closed / Lapsed |