Process for removal of photoresist mask used for making vias in low k carbon-doped silicon oxide dielectric material, and for removal of etch residues from formation of vias and removal of photoresist mask

A process for removing etch residues from vias and for removing a photoresist mask used to form said vias in low k carbon-doped silicon oxide dielectric material while inhibiting damage to said low k silicon oxide dielectric material using a reducing plasma followed by an oxidizing plasma by which comprises:

• a) exposing said photoresist mask and said vias to a plasma formed from one or more reducing agents selected from the group consisting of ammonia, hydrogen, a mixture of ammonia and hydrogen, a mixture of ammonia and nitrogen, a mixture of hydrogen and nitrogen, and a mixture of ammonia, hydrogen, and nitrogen, to remove at least a portion of said resist mask and at least at least a portion of said etch residues in said vias;
• and
• b) then exposing said vias and any remaining portions of said resist mask to a directional beam of charged particles from a plasma of said one or more oxidizing agents, and further characterized by the substantial absence of uncharged radicals, said one or more oxidizing agents further comprising a combination of oxygen and at least one further gas selected from the group consisting of nitrogen and argon, to remove the remainder of said etch residues in said vias and any remaining portions of said photoresist mask.