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US5742555A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of anti-fuse repair

Assignee: Mosaid Technologies Inc
•
Filing: 1996-08-20
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Granted: 1998-04-21
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Expires: 2016-08-20
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Abstract

Abstract An integrated circuit anti-fuse is described which is fabricated as a capacitor using a layer of oxide. The two plates of the anti-fuse are coupled to appropriate voltage levels to rupture the oxide and form a conductive short between the plates. One of the plates is formed as a diffused well which is coupled to an external voltage during programming. The well is biased to an internal voltage during normal operation of the circuit incorporating the anti-fuse.

Inventors

  • 👤 Kenneth W. Marr
  • 👤 Shubneesh Batra

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 16:07
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/40; H10W20/49; H10W20/491

Claims Analysis

Total Claims: 29
Claim 1
Independent Claim 68 words
An integrated circuit comprising: an anti-fuse having first and second plates separated by a layer of dielectric; programming circuitry adapted to couple a first potential to the first plate; and a virtual ground coupled to the second plate for providing a second potential to the second plate, such that a differential voltage between the first and second plates is sufficient to create a conductive path through the dielectric.
Claim 2
Dependent Claim 68 words
An integrated circuit comprising: an anti-fuse having first and second plates separated by a layer of dielectric; programming circuitry adapted to couple a first potential to the first plate; and a virtual ground coupled to the second plate for providing a second potential to the second plate, such that a differential voltage between the first and second plates is sufficient to create a conductive path through the dielectric.
Claim 3
Dependent Claim 97 words
An integrated circuit comprising: an anti-fuse having first and second conductive plates; a layer of oxide fabricated between the first and second conductive plates; anti-fuse logic circuitry connected to the first conductive plate for selectively coupling the first conductive plate to a program voltage level; and a bias circuit connected to the second conductive plate for coupling the second conductive plate to a ground voltage level; an external connection connected to the second conductive plate for coupling the second conductive plate to a pre-determined external voltage level during anti-fuse programming, the pre-determined external voltage level being non-zero.
Claim 4
Dependent Claim 97 words
An integrated circuit comprising: an anti-fuse having first and second conductive plates; a layer of oxide fabricated between the first and second conductive plates; anti-fuse logic circuitry connected to the first conductive plate for selectively coupling the first conductive plate to a program voltage level; and a bias circuit connected to the second conductive plate for coupling the second conductive plate to a ground voltage level; an external connection connected to the second conductive plate for coupling the second conductive plate to a pre-determined external voltage level during anti-fuse programming, the pre-determined external voltage level being non-zero.
Claim 5
Dependent Claim 22 words
The integrated circuit of claim 2 wherein the first conductive plate is a layer of polysilicon formed on the layer of oxide.
Claim 6
Dependent Claim 13 words
The integrated circuit of claim 3 wherein the layer of polysilicon is n-type.
Claim 7
Dependent Claim 19 words
The integrated circuit of claim 2 wherein the second conductive plate is a well formed in a silicon substrate.
Claim 8
Dependent Claim 17 words
The integrated circuit of claim 5 wherein the well is n-type and the silicon substrate is p-type.
Claim 9
Dependent Claim 32 words
The integrated circuit of claim 2 wherein the bias circuit comprises a transistor having a first connection coupled to the second conductive plate and a second connection coupled to the ground voltage.
Claim 10
Dependent Claim 157 words
An integrated circuit comprising: an anti-fuse having first and second conductive plates; a layer of oxide fabricated between the first and second conductive plates; anti-fuse logic circuitry connected to the first conductive plate for selectively coupling the first conductive plate to a program voltage level; an external connection connected to the second conductive plate for coupling the second conductive plate to a pre-determined external voltage level during anti-fuse programming, the pre-determined external voltage level being non-zero; a bias circuit connected to the second conductive plate for coupling the second conductive plate to a bias voltage level; and the bias circuit comprises: a transistor having a first connection coupled to the second conductive plate and a second connection coupled to a bias voltage connection to define a current path from the bias voltage connection to the second conductive plate; and a resistor located electrically in the current path between the bias voltage connection to the second conductive plate.
Claim 11
Dependent Claim 157 words
An integrated circuit comprising: an anti-fuse having first and second conductive plates; a layer of oxide fabricated between the first and second conductive plates; anti-fuse logic circuitry connected to the first conductive plate for selectively coupling the first conductive plate to a program voltage level; an external connection connected to the second conductive plate for coupling the second conductive plate to a pre-determined external voltage level during anti-fuse programming, the pre-determined external voltage level being non-zero; a bias circuit connected to the second conductive plate for coupling the second conductive plate to a bias voltage level; and the bias circuit comprises: a transistor having a first connection coupled to the second conductive plate and a second connection coupled to a bias voltage connection to define a current path from the bias voltage connection to the second conductive plate; and a resistor located electrically in the current path between the bias voltage connection to the second conductive plate.
Claim 12
Dependent Claim 119 words
An integrated circuit comprising: an anti-fuse having first and second conductive plates; a layer of oxide fabricated between the first and second conductive plates; anti-fuse logic circuitry connected to the first conductive plate for selectively coupling the first conductive plate to a program voltage level; an external connection connected to the second conductive plate for coupling the second conductive plate to a pre-determined external voltage level during anti-fuse programming, the pre-determined external voltage level being non-zero; a bias circuit connected to the second conductive plate for coupling the second conductive plate to a bias voltage level; and wherein the bias circuit comprises a plurality of transistors connected in series between the second conductive plate and the bias voltage level.
Claim 13
Dependent Claim 119 words
An integrated circuit comprising: an anti-fuse having first and second conductive plates; a layer of oxide fabricated between the first and second conductive plates; anti-fuse logic circuitry connected to the first conductive plate for selectively coupling the first conductive plate to a program voltage level; an external connection connected to the second conductive plate for coupling the second conductive plate to a pre-determined external voltage level during anti-fuse programming, the pre-determined external voltage level being non-zero; a bias circuit connected to the second conductive plate for coupling the second conductive plate to a bias voltage level; and wherein the bias circuit comprises a plurality of transistors connected in series between the second conductive plate and the bias voltage level.
Claim 14
Dependent Claim 15 words
The integrated circuit of claim 2 wherein the integrated circuit device is a memory device.
Claim 15
Dependent Claim 22 words
The integrated circuit of claim 10 wherein the memory device is a static random access memory (SRAM) having redundant memory element circuitry.
Claim 16
Dependent Claim 21 words
The integrated circuit of claim 2 wherein the program voltage level is zero potential and the external voltage is positive potential.
Claim 17
Dependent Claim 75 words
An integrated circuit memory device comprising: an anti-fuse comprising a layer of oxide fabricated between an n-type polysilicon layer and an n-well formed in a substrate; program circuitry connected to the n-type polysilicon layer for providing a program voltage to the n-type polysilicon layer; an external connection coupled to the n-well for providing an external voltage to the n-well; and a bias circuit connected to the n-well for coupling the n-well to a ground voltage.
Claim 18
Dependent Claim 75 words
An integrated circuit memory device comprising: an anti-fuse comprising a layer of oxide fabricated between an n-type polysilicon layer and an n-well formed in a substrate; program circuitry connected to the n-type polysilicon layer for providing a program voltage to the n-type polysilicon layer; an external connection coupled to the n-well for providing an external voltage to the n-well; and a bias circuit connected to the n-well for coupling the n-well to a ground voltage.
Claim 19
Dependent Claim 32 words
The integrated memory circuit of claim 13 wherein the bias circuit comprises a first transistor having a first connection coupled to the n-well and a second connection coupled to the bias voltage.
Claim 20
Dependent Claim 29 words
The integrated memory circuit of claim 14 wherein the bias circuit further comprises a second transistor connected between the second connection of the first transistor and the bias voltage.
Claim 21
Dependent Claim 24 words
The integrated memory circuit of claim 13 wherein the integrated memory circuit is a static random access memory (SRAM) having redundant memory element circuitry.
Claim 22
Dependent Claim 22 words
The integrated memory circuit of claim 13 wherein the program voltage level is zero potential and the external voltage is positive potential.
Claim 23
Dependent Claim 63 words
An integrated circuit memory device comprising: an external connection coupled to an anti-fuse comprising a layer of oxide fabricated between a polysilicon layer and a well formed in a substrate, and a bias circuit connected to the well for coupling the well to a ground voltage; and program circuitry connected to the polysilicon layer for providing a program voltage to the polysilicon layer.
Claim 24
Dependent Claim 63 words
An integrated circuit memory device comprising: an external connection coupled to an anti-fuse comprising a layer of oxide fabricated between a polysilicon layer and a well formed in a substrate, and a bias circuit connected to the well for coupling the well to a ground voltage; and program circuitry connected to the polysilicon layer for providing a program voltage to the polysilicon layer.
Claim 25
Independent Claim 81 words
A method of programming an integrated circuit anti-fuse, the anti-fuse comprising first and second conductive plates having a layer of oxide fabricated therebetween, the method comprising the steps of: coupling the first conductive plate to a program voltage; coupling the second conductive plate to an opposite voltage through an external connection to create a current path through the layer of oxide to electrically connect the first and second conductive layers; and coupling the well to zero potential through a bias circuit.
Claim 26
Independent Claim 81 words
A method of programming an integrated circuit anti-fuse, the anti-fuse comprising first and second conductive plates having a layer of oxide fabricated therebetween, the method comprising the steps of: coupling the first conductive plate to a program voltage; coupling the second conductive plate to an opposite voltage through an external connection to create a current path through the layer of oxide to electrically connect the first and second conductive layers; and coupling the well to zero potential through a bias circuit.
Claim 27
Dependent Claim 30 words
The method of claim 19 wherein the first conductive layer is fabricated as a polysilicon layer, and the second conductive plate is fabricated as a well in a silicon substrate.
Claim 28
Dependent Claim 21 words
The method of claim 19 wherein the program voltage is zero potential, and the opposite voltage is a pre-determined positive potential.
Claim 29
Dependent Claim 13 words
The method of claim 19 wherein the integrated circuit device is a memory.

References Cited (Backward Citations)

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US5324681A Cited
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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) 2001-04-20 2001-10-20 2002-04-21 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2005-04-20 2005-10-20 2006-04-21 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2009-04-20 2009-10-20 2010-04-21 $7700.00 Window Closed / Lapsed

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