Selectively etching metals and metal nitrides conformally

A method of etching a metal-and-nitrogen-containing layer, the method comprising:

• placing a patterned substrate into a substrate processing region of a substrate processing chamber, wherein the patterned substrate comprises an exposed portion of the metal-and-nitrogen-containing layer, wherein the metal layer comprises a first metal element and nitrogen;
• and
• flowing an oxygen-containing precursor into the substrate processing region;
• oxidizing the exposed portion of the metal-and-nitrogen-containing layer, wherein oxidizing the exposed portion produces an oxidized portion of the metal-and-nitrogen-containing layer and leaves behind an unoxidized portion of the metal-and-nitrogen-containing layer;
• and
• flowing a metal-and-halogen-containing precursor into the substrate processing region;
• selectively etching the oxidized portion of the metal-and-nitrogen-containing layer, wherein the metal-and-halogen-containing precursor comprises a second metal element and a halogen.

A method of etching a metal-containing layer, the method comprising:

• placing a patterned substrate into a substrate processing region of a substrate processing chamber, wherein the patterned substrate comprises an exposed portion of the metal-containing layer as well as exposed regions of a silicon-containing material, wherein the metal-containing layer comprises a first metal element;
• and
• removing a cycle thickness of the metal-containing layer with a processing cycle of:
• i) flowing an oxygen-containing precursor into the substrate processing region, oxidizing the exposed portion of the metal-containing layer, wherein oxidizing the exposed portion creates an oxidized portion of the metal-containing layer but leaves behind an unoxidized portion of the metal-containing layer;
• and
• ii) flowing a metal-and-halogen-containing precursor into the substrate processing region, removing the oxidized portion of the metal-containing layer and leaving the remaining portion of the metal-containing layer intact, wherein the metal-and-halogen-containing precursor comprises a second metal element and a halogen.