US5196724A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Programmable interconnect structures and programmable integrated circuits
Assignee: QuickLogic Corp
•
Filing: 1992-04-23
•
Granted: 1993-03-23
•
Expires: 2012-04-23
Abstract
Abstract An amorphous silicon antifuse has a bottom electrode, a dielectric overlying the bottom electrode, amorphous silicon contacting the bottom electrode in a via in the dielectric, and the top electrode over the amorphous silicon. Spacers are provided in the via corners between the amorphous silicon and the top electrode. The spacers smooth the surface above the amorphous silicon, provide good top electrode step coverage, and reduce leakage current. Another amorphous silicon antifuse is provided in which the amorphous silicon layer is planar. The planarity makes the amorphous silicon layer easy to manufacture. A programmable CMOS circuit is provided in which the antifuse are formed over the intermetal dielectric. The antifuse are not affected by the high temperatures associated with the formation of the intermetal dielectric and the first-metal contacts. The intermetal dielectric protects the circuit elements during the antifuse formation. The bottom electrodes of the antifuses are connected to the first-metal contacts. The overall capacitance associated with the antifuses is low, and hence the circuit is fast.
Inventors
- 👤 Kathryn E. Gordon
- 👤 Richard J. Wong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 08:41
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/40; H10W20/49; H10W20/491; H10W20/01; H10W20/031; H10W20/064; H10W20/065
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
103 words
An antifuse formed in an integrated circuit and comprising: a first electrode comprising a metal layer; a material deposited over and contacting said metal layer, said material being non-conductive when said antifuse is unprogrammed, said material being conductive when said antifuse is programmed; a dielectric overlaying said material and having an opening therethrough; and a second electrode in said opening, said second electrode overlaying and contacting said material, wherein said material has a substantially uniform thickness and a substantially planar surface under said opening in said dielectric, and said first electrode also has a substantially planar surface under said opening in said dielectric.
Claim 2
Dependent Claim
103 words
An antifuse formed in an integrated circuit and comprising: a first electrode comprising a metal layer; a material deposited over and contacting said metal layer, said material being non-conductive when said antifuse is unprogrammed, said material being conductive when said antifuse is programmed; a dielectric overlaying said material and having an opening therethrough; and a second electrode in said opening, said second electrode overlaying and contacting said material, wherein said material has a substantially uniform thickness and a substantially planar surface under said opening in said dielectric, and said first electrode also has a substantially planar surface under said opening in said dielectric.
Claim 3
Dependent Claim
11 words
The antifuse of claim 1 wherein said material comprises amorphous silicon.
Claim 4
Dependent Claim
10 words
The antifuse of claim 1 wherein said material is planar.
Claim 5
Dependent Claim
193 words
A programmable integrated circuit comprising: a semiconductor structure having circuit elements in a substrate; a first conductive layer overlaying said substrate, said first conductive layer being patterned to provide a first level of routing channels, said first level channels being connected to selected circuit elements; a first dielectric layer overlaying said first conductive layer; a second conductive layer overlaying said first dielectric layer; a programmable material overlaying and contacting said second conductive layer at selected locations; and a third conductive layer overlaying and contacting said programmable material at said locations so that said second conductive layer, said programmable material, and said third conductive layer form at each location an antifuse in which an electrode provided by the second conductive layer is connected to said first conductive layer, wherein said third conductive layer provides also a second level of routing channels which are connected to selected circuit elements and further comprising a plurality of spaced-apart connections connecting said electrodes provided by said second conductive layer to said first conductive layer, said connections reducing connection resistance for said electrodes provided by said second conductive layer, wherein said connections are provided by said third conductive layer.
Claim 6
Dependent Claim
193 words
A programmable integrated circuit comprising: a semiconductor structure having circuit elements in a substrate; a first conductive layer overlaying said substrate, said first conductive layer being patterned to provide a first level of routing channels, said first level channels being connected to selected circuit elements; a first dielectric layer overlaying said first conductive layer; a second conductive layer overlaying said first dielectric layer; a programmable material overlaying and contacting said second conductive layer at selected locations; and a third conductive layer overlaying and contacting said programmable material at said locations so that said second conductive layer, said programmable material, and said third conductive layer form at each location an antifuse in which an electrode provided by the second conductive layer is connected to said first conductive layer, wherein said third conductive layer provides also a second level of routing channels which are connected to selected circuit elements and further comprising a plurality of spaced-apart connections connecting said electrodes provided by said second conductive layer to said first conductive layer, said connections reducing connection resistance for said electrodes provided by said second conductive layer, wherein said connections are provided by said third conductive layer.
Claim 7
Dependent Claim
88 words
The programmable integrated circuit of claim 4 further comprising: a second dielectric layer overlaying said second conductive layer and having an opening therethrough for each antifuse, each opening terminating at said second conductive layer, the programmable material of each antifuse overlaying sidewalls and a bottom of the respective opening, said programmable material having sidewalls overlaying the sidewalls of the respective opening; and spacers overlaying the sidewalls of said programmable material in each opening, said third conductive layer overlaying and contacting said spacers and portions of said programmable material.
Claim 8
Dependent Claim
68 words
The programmable integrated circuit of claim 4 further comprising: a second dielectric layer overlaying said programmable material and such that said third conductive layer overlays said second dielectric layer; and for each antifuse, an opening through said second dielectric layer at the location of the antifuse, wherein, for each opening, said third conductive layer has a portion in the opening which portion overlays and contacts said programmable material.
Claim 9
Dependent Claim
14 words
The programmable integrated circuit of claim 4 wherein said programmable material comprises amorphous silicon.
Claim 10
Dependent Claim
141 words
A programmable interconnect structure comprising: a first conductor; an insulating layer on top of said first conductor, said insulating layer having an opening therethrough; a programmable material overlaying sidewalls and a bottom of said opening, said programmable material being non-conductive when said structure is unprogrammed, said programmable material providing a conductive path therethrough when said structure is programmed, a portion of the programmable material near the sidewalls of said opening being thinner than another portion of the programmable material near a center of said opening; dielectric spacers overlaying said thinner portion of said programmable material; and a second conductor overlaying said spacers and said portions of said programmable material, said second conductor contacting the thicker portion of said programmable material, wherein said spacers reduce leakage current between said first and second conductors through said programmable material when said structure is unprogrammed.
Claim 11
Dependent Claim
141 words
A programmable interconnect structure comprising: a first conductor; an insulating layer on top of said first conductor, said insulating layer having an opening therethrough; a programmable material overlaying sidewalls and a bottom of said opening, said programmable material being non-conductive when said structure is unprogrammed, said programmable material providing a conductive path therethrough when said structure is programmed, a portion of the programmable material near the sidewalls of said opening being thinner than another portion of the programmable material near a center of said opening; dielectric spacers overlaying said thinner portion of said programmable material; and a second conductor overlaying said spacers and said portions of said programmable material, said second conductor contacting the thicker portion of said programmable material, wherein said spacers reduce leakage current between said first and second conductors through said programmable material when said structure is unprogrammed.
Claim 12
Dependent Claim
45 words
The programmable interconnect structure of claim 8 wherein said programmable material has a first portion covering the sidewalls of said opening and a second portion covering the bottom of said opening, said first and second portions forming a step; and said spacers smooth said step.
Claim 13
Dependent Claim
38 words
The programmable interconnect structure of claim 8 wherein said second 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 14
Dependent Claim
20 words
The programmable interconnect structure of claim 10 wherein said conductive material comprises aluminum; and said programmable material comprises amorphous silicon.
Claim 15
Dependent Claim
14 words
The programmable interconnect structure of claim 8 wherein said programmable material comprises amorphous silicon.
References Cited (Backward Citations)
US3675090A
Cited
US4424578A
Cited
US4519849A
Cited
US4499557A
Cited
US4569121A
Cited
US4569120A
Cited
US4847732A
Cited
JPS60128640A
Cited
US4651409A
Cited
US4751197A
Cited
US4641420A
Cited
US4943538A
Cited
US4823181A
Cited
US4758745B1
Cited
US4857774A
Cited
US4873459A
Cited
US4910417A
Cited
US4873459B1
Cited
US4758745A
Cited
US4862243A
Cited
US4962414A
Cited
US4898841A
Cited
US4882611A
Cited
JPH02146745A
Cited
US5011791A
Cited
US4914055A
Cited
US5066612A
Cited
US5106773A
Cited
US5120679A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-03-22 | 1996-09-21 | 1997-03-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-03-22 | 2000-09-21 | 2001-03-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-03-22 | 2004-09-21 | 2005-03-23 | $7700.00 | Window Closed / Lapsed |