Method of etching a polysilicon layer during the stripping of the photoresist shape used as an etch mask to create an opening to an underlying fuse structure

Abstract

A process for creating a fuse structure opening in a stack of materials comprised with overlying dielectric layers, and comprised with an underlying polysilicon layer, to expose a conductive fuse structure, has been developed. The process initiates with a dry etching procedure used to create an initial fuse structure opening in the dielectric layers, using a photoresist shape as an etch mask. Subsequent removal of the photoresist shape results in the completion of the fuse structure opening via in situ etching of the polysilicon layer exposed in the initial fuse structure opening. The isotropic wet etch procedure used for photoresist removal and in situ patterning of polysilicon, avoids polysilicon spacer formation on the sides of the conductive fuse structure, which would have been present with the use of an all dry etch procedure. In addition the wet etch procedure selectively terminates on a thin silicon oxide layer, located on the underlying conductive fuse structure.