Method of making a disposable corner etch stop-spacer for borderless contacts

摘要

A borderless contact method for a semiconductor device is disclosed employing a disposable etch stopping spacer to protect the upper edges of adjacent structure during contact hole etching. An exemplary FET gate structure is formed on a substrate adjacent to a source or drain diffusion region. A layer of dielectric material is deposited over the structure including the gate stack. An etch stopping spacer, of a material selectively etchable relative to the dielectric material is placed upon the sidewalls and the upper edges of the gate stack. The resulting structure is blanketed with a glass layer which is selectively masked and etched to provide a hole for making a borderless contact to the substrate adjacent to the gate stack. The spacer itself can be etched away prior to filling the hole with contact material in order to maximize the contact area.