US5521440A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low-capacitance, plugged antifuse and method of manufacture therefor
Assignee: Crosspoint Solutions Inc
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Filing: 1994-05-25
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Granted: 1996-05-28
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Expires: 2014-05-25
Abstract
Abstract An antifuse structure in an integrated circuit is provided. The antifuse structure has a first metal interconnection line and a first insulating layer over the first metal interconnection line. The first insulating layer has a via exposing a top surface of the first metal interconnection line. In the first aperture a metal plug contacts the first metal interconnection layer and has a top surface substantially coplanar with a top surface of the first insulating layer. A metal pad contacts and covers the top surface of the metal plug. The metal pad should be formed by a viscous barrier metal, such as TiW, to smooth the surface of the metal plug. A second insulating layer, relatively thin with respect to said first insulating layer, covers the metal pad and has an aperture exposing a top surface of the metal pad. A programming layer deposited over the second insulating layer and into the aperture contacts the top surface of metal pad. A second metal interconnection line rests on the programming layer. In an alternative embodiment the locations of the second insulating layer and the programming layer are reversed.
Inventors
- 👤 Ali Iranmanesh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 08:50
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/40; H10W20/49; H10W20/491; H10W20/41; H10W20/42
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
183 words
An antifuse structure in an integrated circuit comprising a first metal interconnection line; a first insulating layer over said first metal interconnection line, said first insulating layer having a first aperture exposing a top surface of said first metal interconnection line; a metal plug in said first aperture, said metal plug contacting said first metal interconnection layer and having a top surface substantially coplanar with a top surface of said first insulating layer; a metal pad in contact with and covering said top surface of said metal plug, said metal pad having a periphery substantially coextensive with a periphery of said metal plug; a second insulating layer over said metal pad, said second insulating layer being thin with respect to said first insulating layer, said second insulating layer having a second aperture exposing a top surface of said metal pad; a programming layer over said second insulating layer and in said second aperture to contact said top surface of metal pad; and a second interconnection line over said programming layer; whereby said antifuse structure has a low capacitance and a consistent programming voltage.
Claim 2
Dependent Claim
183 words
An antifuse structure in an integrated circuit comprising a first metal interconnection line; a first insulating layer over said first metal interconnection line, said first insulating layer having a first aperture exposing a top surface of said first metal interconnection line; a metal plug in said first aperture, said metal plug contacting said first metal interconnection layer and having a top surface substantially coplanar with a top surface of said first insulating layer; a metal pad in contact with and covering said top surface of said metal plug, said metal pad having a periphery substantially coextensive with a periphery of said metal plug; a second insulating layer over said metal pad, said second insulating layer being thin with respect to said first insulating layer, said second insulating layer having a second aperture exposing a top surface of said metal pad; a programming layer over said second insulating layer and in said second aperture to contact said top surface of metal pad; and a second interconnection line over said programming layer; whereby said antifuse structure has a low capacitance and a consistent programming voltage.
Claim 3
Dependent Claim
15 words
The antifuse structure of claim 1 wherein said metal pad comprises a viscous barrier metal.
Claim 4
Dependent Claim
12 words
The antifuse structure of claim 2 wherein said metal pad comprises TiW.
Claim 5
Dependent Claim
12 words
The antifuse structure of claim 2 wherein said metal pad comprises TiN.
Claim 6
Dependent Claim
14 words
The antifuse structure of claim 2 wherein said metal pad comprises MoSi 2 .
Claim 7
Dependent Claim
13 words
The antifuse structure of claim 1 wherein said programming layer comprises amorphous silicon.
Claim 8
Dependent Claim
12 words
The antifuse structure of claim 1 wherein said metal plug comprises tungsten.
Claim 9
Dependent Claim
12 words
The antifuse structure of claim 1 wherein said metal plug comprises aluminum.
Claim 10
Dependent Claim
29 words
The antifuse structure of claim 8 wherein said first metal interconnection line comprises an aluminum layer and a barrier metal layer between said aluminum layer and said metal plug.
Claim 11
Dependent Claim
29 words
The antifuse structure of claim 1 wherein said second metal interconnection line comprises an aluminum layer, and a barrier metal layer between said programming layer and said metal plug.
Claim 12
Dependent Claim
29 words
The antifuse structure of claim 1 wherein said first insulating layer is from 5000 to 15000 Å thick and said second insulating layer is 500 to 3000 Å thick.
Claim 13
Dependent Claim
15 words
The antifuse structure of claim 1 wherein said metal pad comprises a smooth top surface.
Claim 14
Dependent Claim
185 words
An antifuse structure in an integrated circuit comprising a first metal interconnection line; a first insulating layer over said first metal interconnection line, said first insulating layer having a first aperture exposing a top surface of said first metal interconnection line; a metal plug in said first aperture, said metal plug contacting said first metal interconnection layer and having a top surface substantially coplanar with a top surface of said first insulating layer; a metal pad in contact with and covering said top surface of said metal plug, said metal pad having a periphery substantially coextensive with a periphery of said metal plug; a programming layer over said metal pad; a second insulating layer over said programming layer, said second insulating layer relatively thin with respect to said first insulating layer, said second insulating layer having a second aperture over said metal pad and exposing a top surface of said programming layer; and a second interconnection line over said second insulating layer and in said second aperture to contact said programming layer; whereby said antifuse structure has a low capacitance and a consistent programming voltage.
Claim 15
Dependent Claim
185 words
An antifuse structure in an integrated circuit comprising a first metal interconnection line; a first insulating layer over said first metal interconnection line, said first insulating layer having a first aperture exposing a top surface of said first metal interconnection line; a metal plug in said first aperture, said metal plug contacting said first metal interconnection layer and having a top surface substantially coplanar with a top surface of said first insulating layer; a metal pad in contact with and covering said top surface of said metal plug, said metal pad having a periphery substantially coextensive with a periphery of said metal plug; a programming layer over said metal pad; a second insulating layer over said programming layer, said second insulating layer relatively thin with respect to said first insulating layer, said second insulating layer having a second aperture over said metal pad and exposing a top surface of said programming layer; and a second interconnection line over said second insulating layer and in said second aperture to contact said programming layer; whereby said antifuse structure has a low capacitance and a consistent programming voltage.
Claim 16
Dependent Claim
16 words
The antifuse structure of claim 13 wherein said metal pad comprises a viscous barrier metal layer.
Claim 17
Dependent Claim
12 words
The antifuse structure of claim 14 wherein said metal pad comprises TiW.
Claim 18
Dependent Claim
12 words
The antifuse structure of claim 14 wherein said metal pad comprises TiN.
Claim 19
Dependent Claim
14 words
The antifuse structure of claim 14 wherein said metal pad comprises MoSi 2 .
Claim 20
Dependent Claim
13 words
The antifuse structure of claim 13 wherein said programming layer comprises amorphous silicon.
Claim 21
Dependent Claim
12 words
The antifuse structure of claim 13 wherein said metal plug comprises tungsten.
Claim 22
Dependent Claim
12 words
The antifuse structure of claim 13 wherein said metal plug comprises aluminum.
Claim 23
Dependent Claim
29 words
The antifuse structure of claim 13 wherein said second metal interconnection line comprises an aluminum layer and a barrier metal layer between said aluminum layer and said programming layer.
Claim 24
Dependent Claim
29 words
The antifuse structure of claim 21 wherein said first metal interconnection line comprises an aluminum layer and a barrier metal layer between said aluminum layer and said metal plug.
Claim 25
Dependent Claim
29 words
The antifuse structure of claim 13 wherein said first insulating layer is from 5000 to 15000 Å thick and said second insulating layer is 500 to 3000 Å thick.
Claim 26
Dependent Claim
15 words
The antifuse structure of claim 13 wherein said metal pad comprises a smooth top surface.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-05-28 | 1999-11-27 | 2000-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-05-28 | 2003-11-27 | 2004-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-05-28 | 2007-11-27 | 2008-05-28 | $7700.00 | Window Closed / Lapsed |