Methods of selectively removing post-etch polymer material and dielectric
antireflective coatings (DARC) without substantially etching an underlying carbon-doped
low k dielectric layer, and compositions for the selective removal of a DARC layer
and post-etch polymer material are provided. A composition comprising trimethylammonium
fluoride is used to selectively etch a dielectric antireflective coating layer
overlying a low k dielectric layer at an etch rate of the antireflective coating
layer to the low k dielectric layer that is greater than the etch rate of the antireflective
coating to a TEOS layer. The method and composition are useful, for example, in
the formation of high aspect ratio openings in low k (carbon doped) silicon oxide
dielectric layers and maintaining the integrity of the dimensions of the formed
openings during a cleaning step to remove a post-etch polymer and antireflective coating.
