Substrate processing apparatus, cleaning substrate processing apparatus cleaning method, and substrate processing method including the same

A substrate processing method comprising:

• processing a first substrate by using a substrate processing apparatus;
• and
• after processing the first substrate, unloading the first substrate from the substrate processing apparatus and then cleaning the substrate processing apparatus,
• wherein the cleaning the substrate processing apparatus comprises:
• supplying a first gas to the substrate processing apparatus to remove a first material deposited in the substrate processing apparatus, wherein the first gas comprises a chlorine-based gas comprising a titanium (III) chloride (TiCl3) gas;
• after the supplying the first gas, removing the first gas from the substrate processing apparatus by supplying the substrate processing apparatus with a purge gas;
• and
• after the removing the first gas, supplying the substrate processing apparatus with a second gas to remove a second material deposited in the substrate processing apparatus, wherein the second material is produced during the removal of the first material by the first gas, and wherein the second gas comprises a fluorine-based gas.