An apparatus for performing a plasma-etching of a LSI device including a Cu interconnection,
a low-k film, and a diffusion prevention film has a treatment chamber, into which
an etching gas is introduced, and a support table which is equipped with electrodes
and on which said LSI device is placed. In this apparatus, the etching gasses are
turned into plasma by supplying radio frequency power to electrodes provided within
the treatment chamber, so that the LSI device is etched with ions of the plasma.
In this apparatus, a sulfur-containing gas and a fluorine-containing gas are mixed
to the etching gasses, so that the diffusion prevention film is selectively etched
against the low-k film.
