Programmable anti-fuse device and method for manufacturing the same

Claim 1

An electrically programmable anti-fuse device comprising: a semiconductor substrate provided with a plurality of functional elements; a field oxide layer formed on said semiconductor substrate for electrically isolating the functional elements from each other; a predetermined pattern of a first electrode of a polysilicon layer doped with a high concentration of an impurity ion formed on said field oxide layer; a first insulating layer on said field oxide layer as well as both end portions and center portion of said first electrode, said first insulating layer having one contact hole which exposes only a portion of said first electrode and a further contact hole which is isolated from said one contact hole, and each said contact hole only exposing a separate portion of said first electrode; second insulating layer formed only in each of said contact holes and serving as an interlayer; and a second and a third electrode of an aluminum based alloy extending respectively into said one contact hole and said further contact hole and formed vertically on said second insulating layers in said one contact hole and said further contact hole, said second and third electrodes being electrically isolated from each other by said first insulating layer such that a circuit can be made between said second electrode and said first electrode and between said third electrode and said first electrode upon the application of a fusing process; whereby should one of said second or third electrodes be defective, the other of said electrodes can be fused to said first electrode upon the application of a fusing process.