Raised tungsten plug antifuse and fabrication processes
First Claim
1. An antifuse comprising:
- a lower conductive electrode having an upper surface and disposed over an insulating layer;
an interlayer dielectric layer disposed over said upper surface of said lower conductive electrode, said interlayer dielectric layer having an upper surface and having an aperture communicating with said lower conductive electrode formed therein;
a conductive plug disposed in said aperture, said conductive plug having an upper surface raised above said upper surface of said interlayer dielectric layer, an outer edge of said upper surface being rounded;
an antifuse layer having a lower surface and an upper surface, said lower surface disposed over and in contact with all of said upper surface of said conductive plug and at least a portion of said upper surface of said interlayer dielectric layer; and
an upper electrode disposed over said upper surface of said antifuse layer.
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Accused Products
Abstract
An antifuse comprises a lower electrode formed from a metal layer in a microcircuit. A interlayer dielectric layer is disposed over the lower electrode and has an aperture formed therein. A conductive plug, formed from a material such as tungsten, is formed in the aperture. The upper surface of the interlayer dielectric is etched back to create a raised portion of the plug. The upper edges of the plug are rounded. An antifuse layer, preferably comprising a silicon nitride, amorphous silicon, silicon nitride sandwich incorporating a thin silicon dioxide layer above or below the amorphous silicon layer or such a sandwich structure covered by a titanium nitride layer, is disposed above the plug. An upper electrode, preferably comprising a metal layer is disposed over the antifuse layer.
112 Citations
12 Claims
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1. An antifuse comprising:
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a lower conductive electrode having an upper surface and disposed over an insulating layer; an interlayer dielectric layer disposed over said upper surface of said lower conductive electrode, said interlayer dielectric layer having an upper surface and having an aperture communicating with said lower conductive electrode formed therein; a conductive plug disposed in said aperture, said conductive plug having an upper surface raised above said upper surface of said interlayer dielectric layer, an outer edge of said upper surface being rounded; an antifuse layer having a lower surface and an upper surface, said lower surface disposed over and in contact with all of said upper surface of said conductive plug and at least a portion of said upper surface of said interlayer dielectric layer; and an upper electrode disposed over said upper surface of said antifuse layer. - View Dependent Claims (2, 3, 4)
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5. An antifuse comprising:
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a lower conductive electrode having an upper surface and disposed over an insulating layer; an interlayer dielectric layer disposed over said upper surface of said lower conductive electrode, said interlayer dielectric layer having an upper surface and having an aperture communicating with said lower conductive electrode formed therein; a conductive plug disposed in said aperture, said conductive plug having an upper surface raised above said upper surface of said interlayer dielectric layer, an outer edge of said upper surface being rounded; an antifuse layer having a lower surface and an upper surface, said lower surface disposed over and in contact with all of said upper surface of said conductive plug and at least a portion of said upper surface of said interlayer dielectric layer; a layer of titanium nitride having an upper surface and a lower surface disposed over said upper surface of said antifuse layer; and an upper electrode disposed over said upper surface of said layer of titanium nitride. - View Dependent Claims (6, 7, 8)
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9. An antifuse comprising:
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a lower conductive electrode having an upper surface and disposed over an insulating layer; an interlayer dielectric layer disposed over said upper surface of said lower conductive electrode, said interlayer dielectric layer having an upper surface and having an aperture communicating with said lower conductive electrode formed therein; a conductive plug disposed in said aperture, said conductive plug having an upper surface raised above said upper surface of said interlayer dielectric layer, an outer edge of said upper surface being rounded; a first layer of titanium nitride having an upper surface and disposed over all of said upper surface of said conductive plug and at least a portion of said upper surface of said interlayer dielectric layer; an antifuse layer having a lower surface and an upper surface, said lower surface disposed over and in contact with all of said upper surface of said conductive plug and at least a portion of said upper surface of said interlayer dielectric layer; a second layer of titanium nitride having an upper surface and a lower surface disposed over said upper surface of said antifuse layer; and an upper electrode disposed over said upper surface of said second layer of titanium nitride. - View Dependent Claims (10, 11, 12)
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Specification