Etching method, etching apparatus, and ring member

A method of dry-etching an etching target film formed on a substrate, comprising:

• determining a main component of the etching target film;
• forming, on a surface of a ring member configured to be used to surround the substrate when the substrate is mounted on a mounting table provided in a processing chamber to be etched therein, a film made of a material having a same main component determined as that of the etching target film formed on the substrate by supplying a film forming gas to the ring member;
• loading the substrate into the processing chamber and mounting the substrate on the mounting table;
• etching the etching target film by using a processing gas in a state where the ring member is disposed to surround the substrate;
• and
• when the main component of the etching target film is changed to a different main component, changing the film on the surface of the ring member to be made of the same different main component.

A dry-etching method comprising:

• determining that a main component of a previously etched target film on a substrate is different from that of a to-be-newly-etched target film formed on said substrate;
• replacing a ring member employed in etching the previously etched target film with a new ring member having a film formed on the new ring member, wherein the film made of a material having a same main component determined as that of the to-be-newly-etched target film is formed on a surface of the new ring member on said substrate by supplying a film forming gas to the new ring member;
• loading the substrate having the to-be-newly-etched target film into the processing chamber and mounting the substrate on the mounting table;
• and
• etching the to-be-newly-etched target film by using a processing gas in a state where the new ring member is disposed to surround the substrate.