Method for forming a dual damascene trench and underlying borderless via in low dielectric constant materials

摘要

A method of forming a dual damascene structure in low k dielectric material employs a multiple layer hard mask over the low k dielectric layer. The trench pattern is etched into the hard mask layer, followed by etching of a via pattern. The trench pattern is widened to completely coincide with the via if the via does not fall completely within the trench pattern due to alignment errors. The low dielectric constant material is protected from the photoresist removal process during the patterning and initial formation of the trench and via in the multiple layer hard mask.