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US 6,440,781 B1Granted
Method of adding bias-independent aluminum bridged anti-fuses to a tungsten plug process
AssigneeNational Semiconductor Corporation
InventorsWilliam M. Coppock, Charles Dark
Life of this patent
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Abstract
A three-terminal integrated circuit device structure is provided that relies upon the formation of an anti-fuse through a silicon substrate with the melting and flowing of an aluminum/aluminum alloy to create the current path. The use of an oversized contact permits the Tungsten plug to be eliminated from the anti-fuse structure, but allows the aluminum melt and flow mechanism to be used with a Tungsten plug process.
Claims10
A method of forming a bias-independent aluminum bridge anti-fuse in a Tungsten plug process, the method comprising:
- forming an integrated circuit device structure that includes a doped region formed in a silicon substrate, first, second and third spaced-apart contact regions formed on a surface of the doped region, the first and second contact regions, having a layer of gate dielectric material formed thereon, first and second polysilicon regions formed over the gate dielectric material on the first and second contact regions, respectively, a layer of insulating dielectric material formed over the first and second polysilicon regions and over the third contact region, the layer of insulating dielectric material having first and second oversized contact openings formed therein to respectively expose a surface region of the first and second polysilicon regions and having a third contact opening formed therein to expose a surface region of the doped region in the third contact region, conductive plug liner material formed on exposed surfaces of the first and second polysilicon regions, a Tungsten plug formed in the third contact opening, and first, second and third spaced-apart, electrically-insulated aluminum/aluminum alloy contacts formed in electrical contact with the plug liner material formed in the first and second oversized contact openings and with the Tungsten plug;
- applying sufficient voltage to the first aluminum/aluminum alloy contact and the Tungsten plug to rupture the dielectric material oxide on the first contact region;
- applying sufficient voltage to the second aluminum/aluminum alloy contact and the Tungsten plug to rupture the gate dielectric material on the second contact region;
- and
- providing sufficient current flow between the first and second aluminum alloy contacts to melt the plug liner material in the first and second polysilicon regions, thereby flowing the aluminum/aluminum alloy between the first and second aluminum/aluminum alloy contacts and forming a permanent anti-fuse conductive path in the silicon substrate and between the first and second aluminum alloy contacts.
2 more elements
A bias-independent aluminum bridge anti-fuse structure in a Tungsten plug integrated circuit structure, the structure comprising:
- a doped region formed in a silicon substrate;
- first, second and third spaced-apart contact regions formed on a surface of the doped region;
- the first and second contact regions having a layer of gate dielectric material formed thereon;
- first and second polysilicon regions formed over the gate dielectric material on the first and second contact regions, respectively;
- a layer of insulating dielectric material formed over the first and second polysilicon regions, the layer of insulating dielectric material having first and second oversized contact openings formed therein to respectively expose a surface region of the first and second polysilicon regions, and having a third contact opening formed therein to expose a surface region of the doped region in the third contact region;
- conductive plug liner material formed on exposed surface of the first and second polysilicon regions;
- first and second spaced-apart, electrically-insulated aluminum/aluminum alloy oversized contacts formed in the first and second oversized contact openings, respectively, and in electrical contact with the first and second polysilicon regions, respectively;
- and
- a Tungsten plug formed in the third contact opening in electrical contact with the doped region in the third contact region.
6 more elements
Dependencies are inferred from the claim text.