US5573970A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for reducing contamination of anti-fuse material in an anti-fuse structure
Assignee: NXP BV
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Filing: 1995-06-06
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Granted: 1996-11-12
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Expires: 2015-06-06
Abstract
Abstract An anti-fuse structure formed in accordance with the present invention includes a conductive layer base. A layer of anti-fuse material overlies the conductive base layer. On top of the anti-fuse layer is an insulating layer, in which a via hole is formed to the anti-fuse layer. The lateral dimension of the via hole is less than about 0.8 microns. Provided in the via hole is a conductive non-Al plug which overlies a layer of a a conductive barrier material such as TiN or TiW that contacts the anti-fuse material and overlies the insulating layer. Tungsten is effectively used as the non-Al plug. An electrically conductive layer is formed over the plug and is separated from the conductive barrier material overlying the anti-fuse layer by the plug. The structure is then programmable by application of a programming voltage and readable by application of a sensing voltage, which is lower than the programming voltage.
Inventors
- 👤 Dipankar Pramanik
- 👤 Subhash R. Nariani
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 14:53
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/40; H10W20/49; H10W20/491; Y; Y10; Y10S; Y10S148/00; Y10S148/055
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
178 words
A method for making an anti-fuse structure comprising the steps of: forming a conductive base layer; forming a layer of anti-fuse material over said conductive base layer; forming an insulating layer over said anti-fuse layer; forming a via hole having sides and having a lateral dimension no greater than about 0.8 microns through said insulating layer to said anti-fuse layer; and forming a conductive barrier layer consisting of a barrier material selected from the group consisting of TiW, TiN, and chromium, said conductive barrier layer having a first portion overlying said anti-fuse material, a second portion extending upward along said sides of said via hole and a third portion overlying a portion of said insulating layer; providing a conductive non-Al plug above said first portion of said conductive barrier layer; such that said anti-fuse structure may be programmed by providing a programming voltage between said conductive base layer and said conductive barrier layer, and may be read by providing a sensing voltage, which is lower than said programming voltage, between said conductive base layer and said barrier layer.
Claim 2
Independent Claim
178 words
A method for making an anti-fuse structure comprising the steps of: forming a conductive base layer; forming a layer of anti-fuse material over said conductive base layer; forming an insulating layer over said anti-fuse layer; forming a via hole having sides and having a lateral dimension no greater than about 0.8 microns through said insulating layer to said anti-fuse layer; and forming a conductive barrier layer consisting of a barrier material selected from the group consisting of TiW, TiN, and chromium, said conductive barrier layer having a first portion overlying said anti-fuse material, a second portion extending upward along said sides of said via hole and a third portion overlying a portion of said insulating layer; providing a conductive non-Al plug above said first portion of said conductive barrier layer; such that said anti-fuse structure may be programmed by providing a programming voltage between said conductive base layer and said conductive barrier layer, and may be read by providing a sensing voltage, which is lower than said programming voltage, between said conductive base layer and said barrier layer.
Claim 3
Dependent Claim
22 words
A method as recited in claim 1 wherein said lateral dimension of said via hole is no greater than about 0.6 microns.
Claim 4
Dependent Claim
40 words
A method as recited in claim 1 wherein said conductive barrier layer is conformally deposited within said via, and wherein said non-Al plug further includes a W plug within said via hole and in contact with said conductive barrier material.
Claim 5
Dependent Claim
30 words
A method as recited in claim 3 further comprising the step of providing a conductive line comprising aluminum over said conductive barrier layer and in contact with said W plug.
Claim 6
Dependent Claim
33 words
A method as recited in claim 3 wherein said W plug is provided by a deposition process which provides a blanket of tungsten over said conductive barrier layer and within said via hole.
Claim 7
Dependent Claim
29 words
A method as recited in claim 5 further comprising the step of etching-back said blanket of tungsten to substantially remove said blanket of tungsten outside of said via hole.
Claim 8
Dependent Claim
29 words
A method as recited in claim 6 further comprising the step of providing a conductive line comprising aluminum over said insulating layer and in contact with said W plug.
Claim 9
Dependent Claim
25 words
A method as recited in claim 1 wherein said conductive barrier layer comprises TiN, which substantially completely fills said via hole as said non-Al plug.
Claim 10
Dependent Claim
24 words
A method as recited in claim 1 wherein said conductive base layer is provided with a thickness in the range of about 1000-10,000 Å.
Claim 11
Dependent Claim
21 words
A method as recited in claim 9 wherein said conductive base layer is provided with a thickness of about 2200 Å.
Claim 12
Dependent Claim
23 words
A method as recited in claim 1 wherein said anti-fuse material is formed with a thickness in the range of about 500-5,000 Å.
Claim 13
Dependent Claim
20 words
A method as recited in claim 11 wherein said anti-fuse material is formed with a thickness of about 1200 Å.
Claim 14
Dependent Claim
23 words
A method as recited in claim 1 wherein said insulating layer is formed with a thickness in the range of about 1000-10,000 Å.
Claim 15
Dependent Claim
20 words
A method as recited in claim 13 wherein said insulating layer is formed with a thickness of about 3000 Å.
Claim 16
Dependent Claim
24 words
A method as recited in claim 1 wherein said conductive barrier layer is formed with a thickness in the range of about 500-3000 Å.
Claim 17
Dependent Claim
21 words
A method as recited in claim 15 wherein said conductive barrier layer is formed with a thickness of about 1000 Å.
Claim 18
Dependent Claim
35 words
A method as recited in claim 3 wherein said via hole has a depth, and wherein said W plug is provided with a height of at least 1/2 of said depth of said via hole.
Claim 19
Dependent Claim
29 words
A method as recited in claim 5 wherein said blanket layer of tungsten is provided with a thickness of about 0.8 times the lateral dimension of the via hole.
Claim 20
Dependent Claim
25 words
A method as recited in claim 8 wherein said barrier layer has a thickness of about 0.8 times the lateral dimension of the via hole.
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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) | 1999-11-12 | 2000-05-13 | 2000-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-11-12 | 2004-05-13 | 2004-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-11-12 | 2008-05-13 | 2008-11-12 | $7700.00 | Window Closed / Lapsed |