Semiconductor device with fuse

Abstract

A semiconductor device with a fuse is formed on a semiconductor substrate having a base semiconductor substrate and an epitaxial semiconductor layer formed thereon and defining a major surface of the semiconductor substrate. An isolation region is formed in the epitaxial semiconductor so as to completely surround and electrically isolate a selected region of the epitaxial layer on which the narrow, blowable portion of the fuse is disposed. A field oxide layer and an insulating layer are formed, in turn, over the fuse and on the main surface of the semiconductor layer and a passivation layer is formed on the insulating layer having an opening therein defined by interior sidewalls of the passivation layer which surround the selected region and which are disposed interiorally of the isolation region, and through which first opening a corresponding service of the insulating layer is exposed. A nitride layer is formed on the passivation layer, including the sidewalls thereof defining the first opening, and covering the exposed surface portion of the insulating layer, a second opening being formed in the nitride layer and exposing a surface portion of the insulating layer, the second window being smaller than the first window and not greater than the blowable portion of the fuse.