Gas supply system, gas control system, plasma processing apparatus, and gas control method

A gas supply system for supplying gas into a processing chamber, the gas supply system comprising:

• a plurality of gas supply flow paths configured to independently supply the gas to the processing chamber;
• a flow rate controller arranged in each of the plurality of gas supply flow paths;
• a primary-side valve arranged on an upstream side of the flow rate controller in each of the plurality of gas supply flow paths;
• a primary-side gas exhaust flow path which is branched between the flow rate controller and the primary-side valve in each of the plurality of gas supply flow paths and is connected to a primary-side exhaust mechanism;
• a primary-side exhaust valve arranged in the primary-side gas exhaust flow path;
• and
• a secondary-side valve arranged on a downstream side of the flow rate controller in each of the plurality of gas supply flow paths,
• wherein the flow rate controller includes:
• a control valve connected to the primary-side valve and the secondary-side valve;
• and
• a control-side orifice arranged between the control valve and the secondary-side valve.

A gas control system for controlling a supply of gas into a processing chamber, the gas control system comprising:

• a gas supply flow path configured to supply the gas to the processing chamber;
• an orifice arranged in the gas supply flow path;
• a primary-side valve arranged on an upstream side of the orifice in the gas supply flow path;
• a primary-side gas exhaust flow path which is branched between the orifice in the gas supply flow path and the primary-side valve and is connected to a primary-side exhaust mechanism;
• a primary-side exhaust valve arranged in the primary-side gas exhaust flow path;
• a secondary-side valve arranged on a downstream side of the orifice in the gas supply flow path;
• a secondary-side gas exhaust flow path which is branched between the orifice in the gas supply flow path and the secondary-side valve and is connected to a secondary-side exhaust mechanism;
• a secondary-side exhaust valve arranged in the secondary-side gas exhaust flow path;
• and
• a controller configured to independently control opening degrees of the primary-side valve, the primary-side exhaust valve, the secondary-side valve, and the secondary-side exhaust valve,
• wherein the controller is configured to execute:
• a first control to alternately and repeatedly execute supplying the gas into the processing chamber by opening the primary-side valve and the secondary-side valve and closing the primary-side exhaust valve and the secondary-side exhaust valve, and exhausting an interior of the gas supply flow path by closing the primary-side valve and the secondary-side valve and opening the primary-side exhaust valve and the secondary-side exhaust valve;
• and
• a second control to cause the primary-side exhaust mechanism and the secondary-side exhaust mechanism to operate such that at least the gas remains in the interior of the gas supply flow path when exhausting the interior of the gas supply flow path, and
• wherein an internal pressure of the gas supply flow path after the exhausting is 100 Torr or less.