Processing method for recovering a damaged low-k film of a substrate and storage medium

A processing method for performing a recovery process on a damaged layer formed on a surface of a low-k film of a target substrate by introducing a processing gas containing a methyl group into a processing chamber in which the target substrate is accommodated, the method comprising:

• increasing an internal pressure of the processing chamber up to a first pressure lower than a processing pressure for the recovery process by introducing a dilution gas into the processing chamber maintained in a preset depressurized state;
• stopping the introduction of the dilution gas after the internal pressure of the processing chamber reaches the first pressure, and increasing the internal pressure of the processing chamber up to a second pressure as the processing pressure for the recovery process by introducing the processing gas into a region where the target substrate exists within the processing chamber;
• and
• performing the recovery process on the target substrate while the processing pressure is maintained.