| abstract |
Method and apparatus for etching a metal layer disposed on a substrate, such as a photolithographic reticle, are provided. In one aspect, a method is provided for processing a substrate including positioning a substrate having a metal photomask layer disposed on a optically transparent material in a processing chamber, introducing a processing gas processing gas comprising an oxygen containing gas, a chlorine containing gas, at least one of trifluoromethane (CHF3), sulfur hexafluoride (SF6), hexafluoroethane (C2F6) or ammonia (NH3) and optionally a chlorine-free halogen containing gas and/or an inert gas, into the processing chamber, generating a plasma of the processing gas in the processing chamber, and etching exposed portions of the metal layer disposed on the substrate. |