Ultra Narrow Trench Patterning Using Plasma Etching

摘要

A method includes forming a polymer layer on a patterned photo resist. The polymer layer extends into an opening in the patterned photo resist. The polymer layer is etched to expose the patterned photo resist. The polymer layer and a top Bottom Anti-Reflective Coating (BARC) are etched to pattern the top BARC, in which the patterned photo resist is used as an etching mask. The top BARC is used as an etching mask to etching an underlying layer.