Cleaning method and recording medium for recording cleaning program

A method for cleaning a chamber inner wall of an etching apparatus, the method comprising:

• first reforming, by plasma generated from nitrogen-containing gas and hydrogen-containing gas, a surface oxide film of a refractory material or a metal compound attached to the chamber inner wall of the etching apparatus to form a reformed layer, and form a first damage layer below the reformed layer;
• first etching, by plasma generated from fluorine-containing gas and inert gas, the formed reformed layer and the first damage layer to expose the refractory material or the metal compound;
• second reforming, by the plasma generated from the nitrogen-containing gas and the hydrogen-containing gas, the refractory material or the metal compound attached to the chamber inner wall of the etching apparatus to form a second damage layer;
• and
• second etching, by the plasma generated from the fluorine-containing gas and the inert gas, the formed second damage layer, wherein
• the first reforming and the second reforming include reducing a surface of the metal compound using the nitrogen-containing gas and the hydrogen-containing gas,
• the first etching and the second etching include etching the reduced surface using the fluorine-containing gas and the inert gas, and
• the second reforming and the second etching are repeated for a number of times after the first etching,
• wherein the nitrogen-containing gas is N2.