Patent ID: 7785934

Claim:
An electrical fuse fabrication method, comprising: forming a first and second electrically conductive region in a substrate; forming a first dielectric layer comprising a first dielectric material on the substrate and on the first and second electrically conductive regions; forming a first and second opening in the first dielectric layer such that the first and second electrically conductive region is exposed to a surrounding ambient through the first and second opening, respectively; forming a first and second diffusion barrier layer on and in direct physical contact with side walls and bottom walls of the first and second opening, respectively, such that the first and second diffusion barrier layer is electrically coupled to and in direct physical contact with the first and second electrically conductive region, respectively, wherein the first and second diffusion barrier layers are electrically conductive; after said forming the first and second diffusion barrier layers, completely filling the first and second openings with a first electrically conductive material; completely removing the first electrically conductive material from the second opening and not removing the first electrically conductive material from the first opening; after said completely removing the first electrically conductive material from the second opening, completely filling the second opening with a second dielectric material and forming a second dielectric layer comprising the second dielectric material on and above the first and second openings; forming a third and fourth opening in the second dielectric layer such that the first electrically conductive material in the first opening and the second dielectric material in the second opening are exposed to the surrounding ambient through the third and fourth opening, respectively; forming a third and fourth diffusion barrier layer on top of and in direct physical contact with side walls and bottom walls of the third and fourth opening, respectively, such that the third and fourth diffusion barrier layer is electrically coupled to and in direct physical contact with the first electrically conductive material in the first opening and the first diffusion barrier layer, respectively, wherein the third and fourth diffusion barrier layers are electrically conductive; and after said forming the third and fourth diffusion barrier layers, completely filling the fourth opening with a second electrically conductive material resulting in the second electrically conductive material in the fourth opening being electrically coupled to the second electrically conductive region via the fourth diffusion barrier layer and the second diffusion barrier layer.