Method for forming a dual damascene structure

摘要

A method for forming a dual damascene feature is provided. Vias are formed in an etch layer. A trench patterned mask is provided over the etch layer. A trench is etched, where the etching the trench comprises a cycle of forming protective sidewalls over the sidewalls of the vias and etching a trench through the trench patterned mask. The mask is then stripped.