Preweakened on chip metal fuse using dielectric trenches for barrier layer isolation

摘要

A fuse for use in an integrated circuit includes a dielectric layer into which a trench or void is etched defined by a top opening and a bottom floor. The trench includes at least one undercut which forms an overhang in the dielectric layer partially shielding the bottom floor. A second or barrier layer deposited onto the dielectric layer is interrupted or non-continuous at the undercut. A third, or electrically conductive layer, is electrically continuous over the fuse. A weak spot in the third layer exists in the lack of structural support by the second layer at the interruption. A further weak spot in the third layer exists in the electrical isolation of the conductor layer, i.e. no leakage current through the barrier layer, at the interruption.