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US5250464A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of making a low capacitance, low resistance sidewall antifuse structure

Assignee: Texas Instruments Inc
•
Filing: 1992-03-11
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Granted: 1993-10-05
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Expires: 2012-03-11
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Abstract

Abstract A method and resulting structure to provide an antifuse wherein the resistance of the programmed fuse and the line resistance and capacitance are materially reduced relative to the prior art and the procedures involved and the resulting structure of the fuse permit the use of materials not available in prior art antifuses. This is accomplished by providing the fuse on vertical sidewalls of the fuse electrode or beneath a sidewall oxide on the fuse electrode. Since the thickness of the electrode can be controlled to an extent not currently achievable by lithographic means, a much smaller area antifuse is provided using sidewall antifuse as opposed to a planar antifuse. The method of forming the antifuse structure comprises the steps of forming a pedestal having a sidewall comprising a first layer of electrically conductive material and a first electrically insulating layer thereon, forming a conformal layer of electrically conductive material on the pedestal and exposed substrate extending along the sidewall, forming a sidewall insulating layer along the sidewall portion of the layer of electrically conductive material, removing all of the exposed portion of the layer of electrically conductive material while retaining the portion of the layer of electrically conductive material between the pedestal and the sidewall insulating layer, forming a second layer of electrically insulating material over the structure, and forming a second layer of electrically conductive material over the second layer of electrically insulating material.

Inventors

  • 👤 Man Wong
  • 👤 David K. Liu

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 04:32
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/40; H10W20/49; H10W20/491; Y; Y10; Y10S; Y10S148/00; Y10S148/055

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 164 words
A method of forming an antifuse structure comprising the steps of: (a) providing a substrate having an oxide layer on a surface thereof, (b) forming a pedestal having a sidewall on said oxide layer comprising a first layer of electrically conductive material on said oxide layer and a first electrically insulating layer on said first electrically conductive layer remote from said oxide layer, (c) forming a conformal layer of electrically conductive material on said pedestal and exposed substrate extending along said sidewall, (d) forming a sidewall insulating layer along the sidewall portion of said layer of electrically conductive material, (e) removing all of the exposed portion of said layer of electrically conductive material while retaining the portion of said layer of electrically conductive material between said pedestal and said sidewall insulating layer, (f) forming a second layer of electrically insulating material over the structure of (e), and (g) forming a second layer of electrically conductive material over said second layer of electrically insulating material.
Claim 2
Independent Claim 164 words
A method of forming an antifuse structure comprising the steps of: (a) providing a substrate having an oxide layer on a surface thereof, (b) forming a pedestal having a sidewall on said oxide layer comprising a first layer of electrically conductive material on said oxide layer and a first electrically insulating layer on said first electrically conductive layer remote from said oxide layer, (c) forming a conformal layer of electrically conductive material on said pedestal and exposed substrate extending along said sidewall, (d) forming a sidewall insulating layer along the sidewall portion of said layer of electrically conductive material, (e) removing all of the exposed portion of said layer of electrically conductive material while retaining the portion of said layer of electrically conductive material between said pedestal and said sidewall insulating layer, (f) forming a second layer of electrically insulating material over the structure of (e), and (g) forming a second layer of electrically conductive material over said second layer of electrically insulating material.
Claim 3
Dependent Claim 13 words
The method of claim 1 wherein said first electrically conductive layer is polysilicon.
Claim 4
Dependent Claim 15 words
The method of claim 1 wherein said conformal layer of electrically conductive material is polysilicon.
Claim 5
Dependent Claim 15 words
The method of claim 2 wherein said conformal layer of electrically conductive material is polysilicon.
Claim 6
Dependent Claim 16 words
The method of claim 3 wherein said second layer of electrically conductive material is a metal.
Claim 7
Dependent Claim 70 words
The method of claim 1 further including the step of applying a predetermined electrical potential between said first layer of electrically conductive material and said second layer of electrically conductive material sufficient to cause breakdown of the portion of said second layer of electrically insulating material between said first and second layers of electrically conductive material and coupling of said conformal layer and said third layer of electrically conductive material.
Claim 8
Independent Claim 142 words
A method of forming an antifuse structure which comprises the steps of: (a) providing a substrate, (b) forming a pedestal on said substrate having a sidewall and comprising a first electrically conductive layer and a first electrically insulating layer thereover and remote from said substrate, both of said first layers extending to said sidewall, (c) forming a second electrically conductive layer contacting said first electrically conductive layer and disposed along said sidewall, (d) forming a second electrically insulating layer extending along said second electrically conductive layer and remote from said pedestal, leaving exposed portions of said second electrically conductive layer, (e) forming a third electrically insulating layer extending over said exposed portions of said second electrically conductive layer, and (f) forming a third electrically conductive layer disposed over said second electrically insulating layer and closely spaced from said second electrically conductive layer.
Claim 9
Independent Claim 142 words
A method of forming an antifuse structure which comprises the steps of: (a) providing a substrate, (b) forming a pedestal on said substrate having a sidewall and comprising a first electrically conductive layer and a first electrically insulating layer thereover and remote from said substrate, both of said first layers extending to said sidewall, (c) forming a second electrically conductive layer contacting said first electrically conductive layer and disposed along said sidewall, (d) forming a second electrically insulating layer extending along said second electrically conductive layer and remote from said pedestal, leaving exposed portions of said second electrically conductive layer, (e) forming a third electrically insulating layer extending over said exposed portions of said second electrically conductive layer, and (f) forming a third electrically conductive layer disposed over said second electrically insulating layer and closely spaced from said second electrically conductive layer.
Claim 10
Dependent Claim 58 words
The method of claim 7 further including the step of applying a predetermined electrical potential between said first electrically conductive layer and said third electrically conductive layer sufficient to cause breakdown of the portion of said second electrically insulating layer between said second and third electrically conductive layers and coupling of said second and third electrically conductive layers.

References Cited (Backward Citations)

US5110766A Cited
US4966867A Cited
US5089432A Cited
US5106773A Cited
US5100827A Cited
US5120679A Cited
US5110754A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1996-10-04 1997-04-05 1997-10-05 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2000-10-04 2001-04-05 2001-10-05 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2004-10-04 2005-04-05 2005-10-05 $7700.00 Window Closed / Lapsed

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