Substrate processing system and method of determining flow rate of gas

A substrate processing system comprising:

• a substrate processing apparatus;
• a measurement apparatus configured to measure a flow rate of a gas used in the substrate processing apparatus;
• a first controller configured to control the substrate processing apparatus and the measurement apparatus;
• and
• a wiring connected to the first controller,
• wherein the substrate processing apparatus includes
• a chamber,
• a gas supply unit configured to supply a gas to an internal space of the chamber, the gas supply unit including a flow rate controller, a primary valve connected to a primary side of the flow rate controller, a secondary valve connected to a secondary side of the flow rate controller, and a first gas flow channel including a first end, a second end, and a third end, the first end being connected to the secondary valve and the third end being connected to the internal space of the chamber through an on/off valve, and
• an exhaust apparatus connected to the internal space of the chamber through an exhaust flow channel,
• wherein the first controller is configured to control opening and closing of each of the primary valve and the secondary valve, designate the flow rate of the gas to the flow rate controller, and instruct the measurement apparatus to measure the flow rate of the gas,
• the measurement apparatus includes
• a second gas flow channel including a fourth end and a fifth end, the fourth end being connected to the second end of the gas supply unit,
• a third gas flow channel including a sixth end and a seventh end,
• a first valve connected between the fifth end of the second gas flow channel and the sixth end of the third gas flow channel,
• a second valve connected to the seventh end of the third gas flow channel and provided to be capable of being connected to the exhaust apparatus,
• one or more pressure sensors configured to measure a pressure within the third gas flow channel,
• a temperature sensor configured to measure a temperature within the third gas flow channel, and
• a second controller configured to control opening and closing of each of the first valve and the second valve and perform measurement of the flow rate based on an instruction from the first controller, and
• wherein the first controller is configured to output a voltage through the wiring to open the secondary valve,
• the measurement apparatus includes a relay provided on the wiring, and
• the second controller is configured to control the relay.