Improved techniques for forming electrically blowable fuses on an integrated circuit

摘要

A method for fabricating an electrically blowable fuse on a semiconductor substrate. The method includes forming a fuse portion 102 on the semiconductor substrate. The fuse portion is configured to turn substantially non-conductive when a current exceeding a predefined current level passes through the fuse portion. The method also includes depositing a substantially conformal first layer 302 of dielectric material above the fuse portion and depositing a second layer 304 of dielectric material above the first layer, thereby forming a protrusion of dielectric material above the fuse portion. The second layer being different from the first layer. The method further includes performing chemical-mechanical polish on the protrusion to form an opening through the second layer above the protrusion. There is also included etching, in a substantially isotropic manner, a portion of the first layer through the opening to form a microcavity 502 about the fuse portion. The etching is substantially selective to the second layer and the fuse portion. Additionally, there is included depositing a substantially conformal third layer 606 of dielectric material above the second layer, thereby closing the opening in the second layer.