Abstract: A method for making an anti-fuse structure characterized by the steps of forming a conductive base layer; forming an anti-fuse layer over the base layer; patterning the anti-fuse layer to form an anti-fuse island; forming an insulating layer over the anti-fuse island; forming a via hole through the insulating layer to the anti-fuse island; forming a conductive connection layer over the insulating layer and within the via hole; and patterning the conductive connection layer to form a conductive contact to the anti-fuse island. Preferably, the anti-fuse island comprises amorphous silicon which can optionally be covered with a thin layer of a titanium-tungsten alloy.

Abstract: An anti-fuse structure characterized by a substrate, an oxide layer formed over the substrate having an opening formed therein, an amorphous silicon material disposed within the opening and contacting the substrate, a conductive protective material, such as titanium tungsten, disposed over the amorphous silicon material, and oxide spacers lining the walls of a recess formed within the protective material. The protective material and the spacers provide tighter programming voltage distributions for the anti-fuse structure and help prevent anti-fuse failure.

Abstract: An anti-fuse structure characterized by a substrate, an oxide layer formed over the substrate having an opening formed therein, an amorphous silicon material disposed within the opening and contacting the substrate, and oxide spacers lining the walls of a recess formed within the amorphous silicon. The spacers prevent failures of the anti-fuse structures by covering cusps formed in the amorphous silicon material. The method of the present invention forms the above-described anti-fuse structure and further solves the problem of removing unwanted spacer material from areas outside of the anti-fuse structure locations.