Abstract: A method for etching a low dielectric material to form sidewall spacers including forming a gate electrode on a substrate, forming a source region and a drain region disposed in a substrate, forming a low dielectric constant film over the gate electrode, source region, and drain region, and etching the low dielectric constant film to form sidewall spacers. The method also includes a first part of the etch process that has a lower oxygen flow rate and a higher power substrate bias than a second part of the etch process. Etching the low dielectric constant film includes exposing the substrate to carbon tetrafluoride, oxygen, nitrogen, and argon.