US5059556A
Expired / Lapsed
US
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Low stress polysilicon microstructures
Assignee: Siemens Automotive LP
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Filing: 1990-03-16
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Granted: 1991-10-22
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Expires: 2010-03-16
Abstract
Abstract Method for relieving stress in silicon microstructures by forming a silicide on the microstructures. Sensors comprising a stress-relieved silicon microstructure are also described.
Inventors
- 👤 Duane T. Wilcoxen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 08:18
CPC Classifications
B; B81; B81B; B81B3/00; B81B3/0064; B81B3/0067; B81B3/0072; G; G01; G01F; G01F1/00; G01F1/68; G01F1/684; G01F1/6845; G01L; G01L9/00; G01L9/0041; G01L9/0042; H; H10; H10P; H10P14/00; H10P14/40; H10P14/412; H10P14/414; B81C; B81C2201/00; B81C2201/01; B81C2201/0161; B81C2201/0163; B81C2201/0167; Y; Y10; Y10S; Y10S148/00; Y10S148/073; Y10S148/159
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
77 words
A method of producing a sensor having a free-standing low stress microstructure, said method of forming the microstructure comprising the steps of: forming a layer of a metal selected from the group consisting of refractory metal and a noble metal on a substrate of polycrystalline silicon to give a metal-coated silicon layer; and sintering said metal-coated silicon layer at a temperature not higher than 500° C. in an inert atmosphere to cause formation of stress-relieving metal silicide.
Claim 2
Independent Claim
77 words
A method of producing a sensor having a free-standing low stress microstructure, said method of forming the microstructure comprising the steps of: forming a layer of a metal selected from the group consisting of refractory metal and a noble metal on a substrate of polycrystalline silicon to give a metal-coated silicon layer; and sintering said metal-coated silicon layer at a temperature not higher than 500° C. in an inert atmosphere to cause formation of stress-relieving metal silicide.
Claim 3
Dependent Claim
23 words
A method according to claim 1, wherein said refractory metal is selected from the group consisting of titanium, tungsten, molybdenum, tantalum and chromium.
Claim 4
Dependent Claim
20 words
A method according to claim 1, wherein said noble metal is selected from the group consisting of platinum and palladium.
Claim 5
Dependent Claim
13 words
A method according to claim 1, wherein said metal silicide is platinum silicide.
Claim 6
Dependent Claim
13 words
A method according to claim 1, wherein said substrate is a top-side structure.
Claim 7
Dependent Claim
22 words
A method according to claim 1, wherein said sintering is carried out at a temperature of about 250° C. to 400° C.
Claim 8
Dependent Claim
21 words
A method according to claim 1, wherein said sintering is carried out for a period of about 45 to 60 minutes.
Claim 9
Dependent Claim
27 words
A method according to claim 1, wherein said stress-relieving metal silicided microstructure has an intrinsic tensile stress of not more than about 10×10 9 dyne/cm 2 .
Claim 10
Dependent Claim
21 words
A method according to claim 8, wherein said stress is about 10×10 7 dyne/cm 2 to 15×10 8 dyne/cm 2 .
Claim 11
Dependent Claim
13 words
A method according to claim 1, wherein said microstructure is a bridge structure.
Claim 12
Dependent Claim
13 words
A method according to claim 1, wherein said microstructure is a cantilever structure.
Claim 13
Independent Claim
76 words
A method of producing a sensor having a free-standing low stress microstructure, said method of forming the microstructure comprising the steps of: forming a layer of platinum on a substrate of polycrystalline silicon to give a platinum-coated silicon layer; and sintering said platinum-coated silicon layer at a temperature of about 250° C. to 400° C. in an inert atmosphere for a period of about 45 to 60 minutes to cause formation of a stress-relieving platinum silicide.
Claim 14
Independent Claim
76 words
A method of producing a sensor having a free-standing low stress microstructure, said method of forming the microstructure comprising the steps of: forming a layer of platinum on a substrate of polycrystalline silicon to give a platinum-coated silicon layer; and sintering said platinum-coated silicon layer at a temperature of about 250° C. to 400° C. in an inert atmosphere for a period of about 45 to 60 minutes to cause formation of a stress-relieving platinum silicide.
Claim 15
Dependent Claim
24 words
A method according to claim 13, wherein said polycrystalline silicon is formed by low pressure chemical vapor deposition of silicon tetrahydride on said substrate.
Claim 16
Dependent Claim
21 words
A method according to claim 13, wherein said layer of platinum is formed by sputtering platinum on said polycrystalline silicon layer.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1994-10-21 | 1995-04-22 | 1995-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-10-21 | 1999-04-22 | 1999-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-10-21 | 2003-04-22 | 2003-10-22 | $7700.00 | Window Closed / Lapsed |