Abstract: The antifuse structure of the present invention includes a bottom planarized electrode, an ILD disposed over the bottom electrode, an antifuse cell opening in and through the ILD exposing the bottom electrode, a first barrier metal layer disposed in the antifuse cell opening to protect the antifuse material layer from diffusion from the bottom electrode and to form an effective bottom electrode of reduced area, hence reducing the capacitance of the device, an antifuse material layer disposed in the antifuse cell opening and over the first barrier metal layer, a second barrier metal layer disposed over the antifuse material layer, and a top electrode disposed over the second barrier metal layer.

Abstract: A method for fabricating a metal-to-metal antifuse comprises the steps of (1) forming and defining a first metal interconnect layer; (2) forming an interlayer dielectric layer; (3) forming an antifuse via in the interlayer dielectric layer to expose the first metal interconnect layer; (4) depositing a via metal layer into a portion of the volume defining the antifuse via; (5) forming a planarizing layer of an insulating material in the antifuse via sufficient to fill a remaining portion of the volume defining the antifuse via; (6) etching the planarizing layer to expose an upper surface of the via metal layer and an upper surface of the interlayer dielectric layer so as to form a substantially planar surface comprising the upper surface of the interlayer dielectric layer, the planarizing layer, and the upper surface of the via metal layer; (7) forming an antifuse material layer over the substantially planar surface; (8) forming a metal capping layer over the antifuse material layer; and (9) defining the antif