Two-step fluorine radical etch of hafnium oxide

A method comprising:

• generating a plasma from a fluorine-containing gas mixture, the plasma comprising fluorine radicals and fluorine ions;
• removing the fluorine ions from the plasma to provide a reactive gas having a higher concentration of fluorine radicals than fluorine ions;
• exposing a substrate comprising a hafnium oxide containing layer to the reactive gas, wherein the reactive gas dopes at least a portion of the hafnium oxide containing layer to form a hafnium oxide containing layer doped with fluorine radicals;
• purging the processing volume to remove doping by-products;
• and,
• exposing the hafnium oxide containing layer doped with fluorine radicals to a nitrogen and hydrogen containing gas mixture and the reactive gas to remove at least a portion of the hafnium oxide layer doped with fluorine radicals, wherein the fluorine-containing gas mixture is free from the nitrogen and hydrogen containing gas mixture.

A method comprising:

• generating a plasma from a fluorine-containing gas mixture comprising NF3 and He, the plasma comprising fluorine radicals and fluorine ions;
• removing a portion of the fluorine ions from the plasma to provide a reactive gas containing the fluorine radicals and substantially free from ions;
• exposing a substrate comprising a hafnium oxide-containing layer to the reactive gas, wherein the reactive gas dopes at least a portion of the hafnium oxide-containing layer to form a hafnium oxide-containing layer doped with fluorine radicals;
• purging the processing volume to remove doping by-products;
• and
• exposing the hafnium oxide-containing layer doped with fluorine radicals to an ammonia (NH3) containing gas mixture and the reactive gas to remove at least a portion of the hafnium oxide-containing layer doped with fluorine radicals, wherein the fluorine-containing gas mixture is free from the ammonia (NH3) containing gas mixture.