Patent ID: 8080473

Claim:
A method of forming a damascene structure on a substrate, comprising: preparing a film stack on said substrate, said film stack comprising a SiCOH-containing layer formed on said substrate, a silicon oxide (SiO x ) layer formed on said SiCOH-containing layer, and a first mask layer formed on said silicon oxide layer; forming a trench pattern in said first mask layer; transferring said trench pattern in said first mask layer to said silicon oxide layer; removing said first mask layer; following said removal of said first mask layer, forming a second mask layer on said silicon oxide layer; forming a via pattern in said second mask layer; transferring said via pattern to said SiCOH-containing layer using a first etching process; removing said second mask layer; following said removal of said second mask layer, transferring said trench pattern in said silicon oxide layer to said SiCOH-containing layer using a second etching process with plasma formed from a process composition consisting of NF 3 and an optional noble gas, and wherein said second etching process achieves etch selectivity between said SiCOH-containing layer and said silicon oxide layer; and removing said silicon oxide layer using a third etching process to expose an upper surface of said SiCOH-containing layer, said third etching process is performed prior to depositing material within said trench pattern and said via pattern in said SiCOH-containing layer to form a metalized trench-via structure.