Electrically-programmable low-impedance anti-fuse element
First Claim
1. An electrically-programmable, low-impedance anti-fuse element, including:
- a p-type semiconductor substrate,a first electrode comprising a diffusion region in said substrate,a dielectric layer over said diffusion region, said dielectric layer including a first silicon dioxide portion and a second silicon nitride portion over said first silicon dioxide portion,a second electrode over said dielectric layer,wherein at least one of said first and said second electrodes is heavily doped or implanted with arsenic such that a high concentration of arsenic atoms exists at the interface between said dielectric layer and said electrode, and a controlled radius conductive filament in said dielectric layer electrically connecting said first and second electrodes.
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Accused Products
Abstract
Electrically-programmable low-impedance anti-fuses are disclosed having capacitor-like structure with very low leakage before programming and a low resistance after programming. The electrically-programmable low-impedance anti-fuses of the present invention include a first conductive electrode which may be formed as a diffusion region in a semiconductor substrate or may be formed from a semiconductor material, such as polysilicon, located above and insulated from the substrate. A dielectric layer, which, in a preferred embodiment includes a first layer of silicon dioxide, a second layer of silicon nitride and a third layer of silicon dioxide, is disposed over the first electrode. A second electrode is formed over the dielectric layer from a semiconductor material such as polysilicon, or a metal having a barrier metal underneath. At least one of the two electrodes of each anti-fuse is highly-doped or implanted with arsenic such that high concentrations of arsenic exist at the interface between the electrode and the dielectric layer. This arsenic will combine with other material and flow into the anti-fuse filament after programmed to form a low resistance controllable anti-fuse link. Circuitry is provided which allows the anti-fuse of the present invention to be programmed by application of a suitable programming voltage to input-output pins of the integrated circuit containing the anti-fuse. Where more than one anti-fuse is to be programmed using the programming voltage applied at the input-output terminals, other additional input-output terminals may serve as address inputs to specify the anti-fuse to be programmed.
In another embodiment of the present invention a programmable read-only memory array comprised of memory cells including an anti-fuse in combination with a single transistor. X-address and Y-address decoder circuits are provided to both program and read the contents of any selected memory cell in the array.
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Citations
38 Claims
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1. An electrically-programmable, low-impedance anti-fuse element, including:
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a p-type semiconductor substrate, a first electrode comprising a diffusion region in said substrate, a dielectric layer over said diffusion region, said dielectric layer including a first silicon dioxide portion and a second silicon nitride portion over said first silicon dioxide portion, a second electrode over said dielectric layer, wherein at least one of said first and said second electrodes is heavily doped or implanted with arsenic such that a high concentration of arsenic atoms exists at the interface between said dielectric layer and said electrode, and a controlled radius conductive filament in said dielectric layer electrically connecting said first and second electrodes. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 38)
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9. An electrically-programmable, low-impedance anti-fuse element, including:
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a p-type semiconductor substrate, a first electrode comprising a diffusion region in said substrate, said region heavily doped with arsenic such that a high concentration of arsenic exists at the surface of said region, a dielectric layer over said diffusion region, said dielectric layer including a first silicon dioxide portion and a second silicon nitride portion over said first silicon dioxide portion, and a second electrode over said dielectric layer, and a controlled radius conductive filament in said dielectric layer electrically connecting said first and second electrodes. - View Dependent Claims (10, 11, 12, 13, 14)
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15. An electrically-programmable, low-impedance anti-fuse element, including:
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a semiconductor substrate, an insulating layer over said semiconductor substrate, a first electrode formed from a conducting material, over said insulating layer, a dielectric layer over said first electrode, said dielectric layer including a first silicon dioxide portion and a second silicon nitride portion over said first silicon dioxide portion, second electrode over said dielectric layer, wherein at least one of said first and second electrodes is heavily doped with arsenic such that a high concentration of arsenic atoms exists at the interface of said dielectric layer and said heavily doped one of said first or second electrodes and a controlled radius conductive filament in said dielectric layer electrically connecting said first and second electrodes. - View Dependent Claims (16, 17, 18, 19, 20, 21)
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22. A semiconductor structure disposed in an integrated circuit, including:
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a plurality of electrically-programmable low-impedance anti-fuses, each of said anti-fuses including a first electrode formed from a conductive material, a dielectric layer over said first electrode, said dielectric layer including a first silicon dioxide portion and a second silicon nitride portion over said first silicon dioxide portion, and a second electrode formed of a conductive material over said dielectric layer, wherein at least one of said first and second electrodes is heavily doped with arsenic such that a heavy concentration of arsenic atoms exists at the interface between said dielectric layer and said electrode, at least one of said electrically-programmable low impedance anti-fuse element including a controlled-radius filament in said dielectric layer electrically connecting said first and second electrodes. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29, 37)
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30. A semiconductor structure disposed in an integrated circuit, including:
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a plurality of electrically-programmable low-impedance anti-fuses, each of said anti-fuses including a first electrode comprising an n-type diffusion region in a p-type semiconductor substrate of said semiconductor structure, a dielectric layer over said first electrode, said dielectric layer including a first silicon dioxide portion and a second silicon nitride portion over said first silicon dioxide portion, and a second electrode formed of a conductive material over said dielectric layer, wherein at least one of said first and second electrodes is heavily doped with arsenic such that a heavy concentration of arsenic atoms exists at the interface between said dielectric layer and said electrode, at least one of said electrically-programmable low impedance anti-fuse elements including a controlled-radius filament in said dielectric layer electrically connecting said first and second electrodes. - View Dependent Claims (31, 32, 33, 34, 35, 36)
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Specification