Plasma processing method

A plasma processing method comprising:

• supplying a first rare gas and a processing gas into a chamber;
• processing a target substrate by plasma of a gaseous mixture obtained by mixing the first rare gas and the processing gas;
• exhausting a gas containing the first rare gas from the chamber by a gas exhaust unit;
• separating the first rare gas from the gas exhausted from the chamber by a separating unit:
• boosting the separated first rare gas;
• and
• accumulating the boosted first rare gas in an accumulation unit,
• wherein in said supplying, the processing gas and the first rare gas supplied from the accumulation unit are supplied into the chamber,
• the method further comprising:
• supplying the first rare gas to a gap between the target substrate and a mounting table that is provided in the chamber and mounts thereon the target substrate, and
• wherein in said supplying the first rare gas to the gap, the first rare gas supplied from the accumulation unit is supplied into the gap.

A plasma processing method comprising:

• supplying a first rare gas and a processing gas into a chamber;
• processing a target substrate by plasma of a gaseous mixture obtained by mixing the first rare gas and the processing gas;
• exhausting a gas containing the first rare gas from the chamber by a gas exhaust unit;
• separating the first rare gas from the gas exhausted from the chamber by a separating unit;
• boosting the separated first rare gas;
• accumulating the boosted first rare gas in an accumulation unit,
• wherein in said supplying, the processing gas and the first rare gas supplied from the accumulation unit are supplied into the chamber,
• operating a first switching valve configured to switch whether to transfer the gas exhausted from the chamber by the gas exhaust unit to the separating unit or to discharge the gas to outside without transferring the gas to the separating unit;
• and
• operating a second switching valve configured to switch whether to supply the first rare gas supplied from the accumulation unit to a gap between the target substrate and a mounting table that is provided in the chamber and mounts thereon the target substrate or to supply a second rare gas different from the first rare gas to the gap.