US4994434A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of forming a barrier layer arrangement for conductive layers on silicon substrates
Assignee: Eastman Kodak Co
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Filing: 1989-03-21
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Granted: 1991-02-19
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Expires: 2009-03-21
Abstract
Abstract A process is disclosed of producing on a crystalline silicon substrate a barrier layer triad capable of protecting a rare earth alkaline earth copper oxide conductive coating from direct interaction with the substrate. A silica layer of at least 2000 Å in thickness is deposited on the silicon substrate, and followed by deposition on the silica layer of a Group 4 heavy metal to form a layer having a thickness in the range of from 1500 to 3000 Å. Heating the layers in the absence of a reactive atmosphere to permit oxygen migration from the silica layer forms a barrier layer triad consisting of a silica first triad layer located adjacent the silicon substrate, a heavy Group 4 metal oxide third triad layer remote from the silicon substrate, and a Group 4 heavy metal silicide second triad layer interposed between the first and third triad layers.
Inventors
- 👤 Liang-Sun Hung
- 👤 John A. Agostinelli
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:17
CPC Classifications
H; H10; H10N; H10N60/00; H10N60/01; H10N60/0268; H10N60/0296; H10N60/0576; H10N60/0632; Y; Y10; Y10S; Y10S505/00; Y10S505/725; Y10S505/73; Y10S505/739; Y10S505/80; Y10S505/815; Y10S505/816; Y10S505/817; Y10S505/818; Y10S505/825; Y10S505/826; Y10S505/831; Y10S505/832; Y10S505/917; Y10S505/918; Y10S505/919; Y10S505/92
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
149 words
A process of producing on a silicon substrate a barrier layer triad interposed between the conductive layer and the silicon substrate comprising forming a silica layer of at least 2000 Å in thickness on the silicon substrate, depositing on the silica at least one Group 4 heavy metal to form a layer having a thickness in the range of from 1500 to 3000 Å, and heating the layers in the absence of a reactive atmosphere sufficiently to permit oxygen migration from the silica layer, thereby forming a barrier layer triad consisting of a first triad layer located adjacent the silicon substrate consisting essentially of silica, a third triad layer remote from the silicon substrate consisting essentially of at least one Group 4 heavy metal oxide, and a second triad layer interposed between the first and third triad layers consisting essentially of at least one Group 4 heavy metal silicide.
Claim 2
Dependent Claim
149 words
A process of producing on a silicon substrate a barrier layer triad interposed between the conductive layer and the silicon substrate comprising forming a silica layer of at least 2000 Å in thickness on the silicon substrate, depositing on the silica at least one Group 4 heavy metal to form a layer having a thickness in the range of from 1500 to 3000 Å, and heating the layers in the absence of a reactive atmosphere sufficiently to permit oxygen migration from the silica layer, thereby forming a barrier layer triad consisting of a first triad layer located adjacent the silicon substrate consisting essentially of silica, a third triad layer remote from the silicon substrate consisting essentially of at least one Group 4 heavy metal oxide, and a second triad layer interposed between the first and third triad layers consisting essentially of at least one Group 4 heavy metal silicide.
Claim 3
Dependent Claim
21 words
A process according to claim 1 wherein oxygen migration is achieved by heating to a temperature of at least 700° C.
Claim 4
Dependent Claim
25 words
A process according to claim 2 wherein oxygen migration is achieved by heating to a temperature in the range of from 750° to 1000° C.
Claim 5
Dependent Claim
25 words
A process according to claim 3 wherein oxygen migration is achieved by heating to a temperature in the range of from 800° to 900° C.
Claim 6
Dependent Claim
23 words
A process according to claim 3 wherein heating to achieve oxygen migration extends over a period of from about 30 to 60 minutes.
Claim 7
Dependent Claim
39 words
A process according to claim 1 wherein the barrier layer triad is further heated in the presence of oxygen to convert the second triad layer to a mixture of silica and at least one Group 4 heavy metal oxide.
Claim 8
Dependent Claim
15 words
A process according to claim 1 wherein silver is coated on the third triad layer.
Claim 9
Dependent Claim
25 words
A process according to claim 7 wherein silver is coated on the third triad layer in a thickness range of from 500 to 2000 Å.
References Cited (Backward Citations)
US4880770A
Cited
US4908346A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-02-18 | 1994-08-20 | 1995-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-02-18 | 1998-08-20 | 1999-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-02-18 | 2002-08-20 | 2003-02-19 | $7700.00 | Window Closed / Lapsed |