Method of forming e-fuse in replacement metal gate manufacturing process

Abstract

Embodiment of the present invention provides a method of forming electronic fuse or commonly known as e-fuse. The method includes forming a polysilicon structure and a field-effect-transistor (FET) structure together on top of a common semiconductor substrate, the FET structure having a sacrificial gate electrode; implanting at least one dopant into the polysilicon structure to create a doped polysilicon layer in at least a top portion of the polysilicon structure; subjecting the polysilicon structure and the FET structure to a reactive-ion-etching (RIE) process, the RIE process selectively removing the sacrificial gate electrode of the FET structure while the doped polysilicon layer being substantially unaffected by the RIE process; and converting the polysilicon structure including the doped polysilicon layer into a silicide to form the electronic fuse.