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US5449947A Expired / Lapsed US ⏱️ 0.0 years remaining

Read-disturb tolerant metal-to-metal antifuse and fabrication method

Assignee: Microsemi SoC Corp
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Filing: 1993-07-07
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Granted: 1995-09-12
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Expires: 2013-07-07
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Abstract

Abstract A "read-disturb" resistant metal-to-metal antifuse includes a lower electrode comprising a first metal layer in a microcircuit structure. An inter-metal dielectric is disposed over the lower electrode and includes an antifuse aperture disposed therein. A first layer of antifuse material is disposed over exposed surface of the lower electrode in the antifuse aperture. A highly conductive layer is disposed over the first region of antifuse material and a second layer of antifuse material is disposed over the highly conductive layer. An upper electrode comprises a second metal layer disposed over the second layer of antifuse material. The first and second layers of antifuse material may comprise single-layer or multi-layer dielectric materials, amorphous silicon, or combinations of these materials. A process for fabricating a read-disturb resistant metal-to-metal antifuse comprises the steps of forming a lower electrode comprising a portion of a first metal layer in a microcircuit structure; forming an inter-metal dielectric layer over the lower electrode; forming an antifuse aperture in the inter-metal dielectric layer to expose the upper surface of the lower electrode; forming a first layer of antifuse material over the exposed surface of the lower electrode in the antifuse aperture; forming a highly conductive layer over the first layer of antifuse material; forming a second layer of antifuse material over the highly conductive layer; and forming an upper electrode comprising a second metal layer over the second layer of antifuse material.

Inventors

  • 👤 Wenn-Jei Chen
  • 👤 Steve S. Chiang
  • 👤 Esam Elashmawi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 02:48
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/40; H10W20/49; H10W20/491

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 95 words
An electrically programmable antifuse comprising: a lower electrode; an inter-metal dielectric layer disposed over said lower electrode, said inter-metal dielectric layer including an antifuse cell opening formed therein; a first layer of antifuse material, said antifuse material disposed in said antifuse cell opening; a highly electrically conductive layer, formed from a metal, said highly electrically conductive layer disposed over said first layer of antifuse material in said antifuse cell opening; and a second layer of antifuse material, said second layer of antifuse material disposed over said highly electrically conductive layer in said antifuse cell opening.
Claim 2
Dependent Claim 95 words
An electrically programmable antifuse comprising: a lower electrode; an inter-metal dielectric layer disposed over said lower electrode, said inter-metal dielectric layer including an antifuse cell opening formed therein; a first layer of antifuse material, said antifuse material disposed in said antifuse cell opening; a highly electrically conductive layer, formed from a metal, said highly electrically conductive layer disposed over said first layer of antifuse material in said antifuse cell opening; and a second layer of antifuse material, said second layer of antifuse material disposed over said highly electrically conductive layer in said antifuse cell opening.
Claim 3
Dependent Claim 80 words
An electrically programmable antifuse structure comprising: a first electrode; an insulating layer disposed over said first electrode; a cell opening completely penetrating said insulating layer and exposing said first electrode; a first layer of an antifuse material disposed in said cell opening; a layer of a highly electrically conductive material, formed from a metal, disposed over said first layer of an antifuse material within said cell opening; and a second layer of an antifuse material disposed in said cell opening.
Claim 4
Dependent Claim 80 words
An electrically programmable antifuse structure comprising: a first electrode; an insulating layer disposed over said first electrode; a cell opening completely penetrating said insulating layer and exposing said first electrode; a first layer of an antifuse material disposed in said cell opening; a layer of a highly electrically conductive material, formed from a metal, disposed over said first layer of an antifuse material within said cell opening; and a second layer of an antifuse material disposed in said cell opening.
Claim 5
Dependent Claim 27 words
An electrically programmable antifuse structure according to claim 2 further comprising a second electrode disposed over and in contact with said second layer of an antifuse material.
Claim 6
Dependent Claim 33 words
An electrically programmable antifuse structure according to claim 3 wherein said layer of a highly electrically conductive material is a material selected from the group consisting of: TiN, Ti, TiW, W, Cu, AlCu.
Claim 7
Dependent Claim 28 words
An electrically programmable antifuse structure according to claim 3 wherein said second electrode comprises a layer of aluminum disposed over a layer fabricated of a diffusion barrier material.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1998-09-11 1999-03-13 1999-09-12 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2002-09-11 2003-03-13 2003-09-12 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2006-09-11 2007-03-13 2007-09-12 $7700.00 Window Closed / Lapsed

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