Patent US5880512A successfully refreshed from Google Patents.
US5880512A
Expired / Lapsed
US
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Programmable interconnect structures and programmable integrated circuits
Assignee: QuickLogic Corp
•
Filing: 1996-12-18
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Granted: 1999-03-09
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Expires: 2016-12-18
Abstract
Abstract Antifuses and gate arrays with antifuses are disclosed that have high thermal stability, reduced size, reduced leakage current, reduced capacitance in the unprogrammed state, improved manufacturing yield, and more controllable electrical characteristics. Some antifuses include spacers in the antifuse via. In some antifuses, the programmable material is planar, and the top or the bottom electrode is formed in the antifuse via. In some gate arrays, the antifuses are formed above the dielectric separating two levels of routing channels rather than below that dielectric.
Inventors
- 👤 Kathryn E. Gordon
- 👤 Richard J. Wong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 15:52
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/40; H10W20/49; H10W20/491; Y; Y10; Y10S; Y10S148/00; Y10S148/055
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
84 words
An antifuse structure comprising: a first metal conductor; an insulating layer overlaying said first metal conductor, the insulating layer having an opening therethrough; a programmable material in the opening, the programmable material being non-conductive when the antifuse is unprogrammed, the programmable material providing a conductive path therethrough when the antifuse is programmed; a second metal conductor overlaying and contacting the programmable material in the opening; and a sidewall spacer in the opening, the sidewall spacer being disposed between the first and second metal conductors.
Claim 2
Dependent Claim
84 words
An antifuse structure comprising: a first metal conductor; an insulating layer overlaying said first metal conductor, the insulating layer having an opening therethrough; a programmable material in the opening, the programmable material being non-conductive when the antifuse is unprogrammed, the programmable material providing a conductive path therethrough when the antifuse is programmed; a second metal conductor overlaying and contacting the programmable material in the opening; and a sidewall spacer in the opening, the sidewall spacer being disposed between the first and second metal conductors.
Claim 3
Dependent Claim
12 words
The antifuse of claim 1 wherein the spacer overlays the programmable material.
Claim 4
Dependent Claim
12 words
The antifuse of claim 1 wherein the spacer underlays the programmable material.
Claim 5
Dependent Claim
12 words
The antifuse of claim 1 wherein the programmable material comprises amorphous silicon.
Claim 6
Dependent Claim
10 words
The antifuse of claim 1 wherein the spacer is dielectric.
Claim 7
Dependent Claim
38 words
The antifuse structure of claim 5 wherein the second metal conductor comprises: a conductive material; and a barrier metal separating said conductive material from said programmable material for preventing the conductive material from spiking into said programmable material.
Claim 8
Dependent Claim
19 words
The antifuse structure of claim 6 wherein: said conductive material comprises aluminum; and said programmable material comprises amorphous silicon.
Claim 9
Dependent Claim
13 words
The antifuse structure of claim 7 wherein the barrier metal comprises titanium tungsten.
Claim 10
Dependent Claim
61 words
The antifuse structure of claim 1 wherein, when said structure is programmed, said conductive path is surrounded laterally by a material whose linear thermal expansion coefficient (LTEC) and an LTEC of said conductive path are such that, at 25° C., neither one of said two LTECs is more than four (4) times greater than the other one of said two LTECs.
Claim 11
Dependent Claim
26 words
The antifuse structure of claim 1 wherein, when said structure is programmed, said conductive path is laterally surrounded by an unprogrammed portion of said programmable material.
Claim 12
Dependent Claim
47 words
The antifuse structure of claim 1 wherein, when said structure is programmed, said conductive path and said insulating layer have, at 25° C., different LTECs such that one of said LTECs is at least five (5) times as great as the other one of said two LTECs.
Claim 13
Dependent Claim
30 words
The antifuse structure of claim 11 wherein, at 25° C., the LTEC of the insulating layer is at least five (5) times lower than the LTEC of the conductive path.
Claim 14
Dependent Claim
11 words
The antifuse of claim 1 wherein the spacer is silicon dioxide.
Claim 15
Dependent Claim
39 words
The antifuse of claim 1 wherein the spacer improves step coverage of the second metal conductor, and wherein the spacer reduces leakage current between the first and second metal conductors through the programmable material when the antifuse is unprogrammed.
Claim 16
Dependent Claim
31 words
The antifuse of claim 1 wherein when the antifuse is programmed, the spacer causes the conductive path through the programmable material to be located farther from a sidewall of the opening.
Claim 17
Independent Claim
131 words
A method for fabricating an antifuse structure for an integrated circuit, the method comprising: fabricating a first metal conductor; fabricating an insulating layer overlaying the first metal conductor; fabricating an opening through the insulating layer and terminating the opening at the first metal conductor; fabricating a programmable material in contact with the first metal conductor in the opening, the programmable material being non-conductive when the antifuse is unprogrammed, the programmable material providing a conductive path therethrough when the antifuse is programmed; fabricating a sidewall spacer which contacts the programmable material, wherein at least a portion of an area of contact between the spacer and the programmable material is located in the opening; and fabricating a second metal conductor contacting and overlaying the programmable material in the opening and overlaying the spacer.
Claim 18
Independent Claim
131 words
A method for fabricating an antifuse structure for an integrated circuit, the method comprising: fabricating a first metal conductor; fabricating an insulating layer overlaying the first metal conductor; fabricating an opening through the insulating layer and terminating the opening at the first metal conductor; fabricating a programmable material in contact with the first metal conductor in the opening, the programmable material being non-conductive when the antifuse is unprogrammed, the programmable material providing a conductive path therethrough when the antifuse is programmed; fabricating a sidewall spacer which contacts the programmable material, wherein at least a portion of an area of contact between the spacer and the programmable material is located in the opening; and fabricating a second metal conductor contacting and overlaying the programmable material in the opening and overlaying the spacer.
Claim 19
Dependent Claim
14 words
The method of claim 16 wherein the spacer is fabricated after the programmable material.
Claim 20
Dependent Claim
44 words
The method of claim 16 wherein the conductive path and the insulating layer have different linear thermal expansion coefficients (LTECs) at 25° C. such that one of said LTECs is at least five (5) times as great as the other one of said LTECs.
Claim 21
Dependent Claim
54 words
The method of claim 16 wherein, when the antifuse structure is programmed, the conductive path is laterally surrounded by a material whose LTEC and an LTEC of the conductive path are such that neither one of said two LTECs is more than four (4) times greater than the other one of said two LTECs.
Claim 22
Dependent Claim
12 words
The method of claim 16 wherein the programmable material comprises amorphous silicon.
Claim 23
Dependent Claim
10 words
The method of claim 16 wherein the spacer is dielectric.
Claim 24
Dependent Claim
37 words
The method of claim 21 wherein the second metal conductor comprises: a conductive material; and a barrier metal separating said conductive material from said programmable material for preventing the conductive material from spiking into said programmable material.
Claim 25
Dependent Claim
18 words
The method of claim 22 wherein: said conductive material comprises aluminum; and said programmable material comprises amorphous silicon.
Claim 26
Dependent Claim
12 words
The method of claim 23 wherein the barrier metal comprises titanium tungsten.
Claim 27
Dependent Claim
11 words
The method of claim 16 wherein the spacer is silicon dioxide.
Claim 28
Dependent Claim
39 words
The method of claim 16 wherein the spacer improves step coverage of the second metal conductor, and wherein the spacer reduces leakage current between the first and second metal conductors through the programmable material when the antifuse is unprogrammed.
Claim 29
Independent Claim
155 words
A method for fabricating an antifuse structure for an integrated circuit, the method comprising: fabricating a first metal conductor; fabricating an insulating layer overlaying the first metal conductor; fabricating an opening through the insulating layer and terminating the opening at the first metal conductor; fabricating a programmable material in contact with the first metal conductor in the opening, the programmable material being non-conductive when the antifuse is unprogrammed, the programmable material providing a conductive path therethrough when the antifuse is programmed; fabricating a sidewall spacer which contacts the programmable material, wherein an area of contact between the spacer and the programmable material is at least partially located in the opening; and fabricating a second metal conductor contacting and overlaying the programmable material in the opening and overlaying the spacer, wherein when the antifuse is programmed, the spacer causes the conductive path through the programmable material to be located farther from a sidewall of the opening.
Claim 30
Independent Claim
155 words
A method for fabricating an antifuse structure for an integrated circuit, the method comprising: fabricating a first metal conductor; fabricating an insulating layer overlaying the first metal conductor; fabricating an opening through the insulating layer and terminating the opening at the first metal conductor; fabricating a programmable material in contact with the first metal conductor in the opening, the programmable material being non-conductive when the antifuse is unprogrammed, the programmable material providing a conductive path therethrough when the antifuse is programmed; fabricating a sidewall spacer which contacts the programmable material, wherein an area of contact between the spacer and the programmable material is at least partially located in the opening; and fabricating a second metal conductor contacting and overlaying the programmable material in the opening and overlaying the spacer, wherein when the antifuse is programmed, the spacer causes the conductive path through the programmable material to be located farther from a sidewall of the opening.
Claim 31
Independent Claim
138 words
A method for fabricating an antifuse structure for an integrated circuit, the method comprising: fabricating a first metal conductor; fabricating an insulating layer overlaying the first metal conductor; fabricating an opening through the insulating layer and terminating the opening at the first metal conductor; fabricating a programmable material in contact with the first metal conductor in the opening, the programmable material being non-conductive when the antifuse is unprogrammed, the programmable material providing a conductive path therethrough when the antifuse is programmed; fabricating a sidewall spacer which contacts the programmable material, wherein an area of contact between the spacer and the programmable material is at least partially located in the opening; and fabricating a second metal conductor contacting and overlaying the programmable material in the opening and overlaying the spacer, wherein the spacer is fabricated before the programmable material.
Claim 32
Independent Claim
138 words
A method for fabricating an antifuse structure for an integrated circuit, the method comprising: fabricating a first metal conductor; fabricating an insulating layer overlaying the first metal conductor; fabricating an opening through the insulating layer and terminating the opening at the first metal conductor; fabricating a programmable material in contact with the first metal conductor in the opening, the programmable material being non-conductive when the antifuse is unprogrammed, the programmable material providing a conductive path therethrough when the antifuse is programmed; fabricating a sidewall spacer which contacts the programmable material, wherein an area of contact between the spacer and the programmable material is at least partially located in the opening; and fabricating a second metal conductor contacting and overlaying the programmable material in the opening and overlaying the spacer, wherein the spacer is fabricated before the programmable material.
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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) | 2002-03-08 | 2002-09-07 | 2003-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-03-08 | 2006-09-07 | 2007-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-03-08 | 2010-09-07 | 2011-03-09 | $7700.00 | Window Closed / Lapsed |