Gas supply system, substrate processing apparatus, and control method for gas supply system

A substrate processing system, comprising:

• a substrate processing chamber having a gas inlet and a gas outlet;
• an exhaust device connected to the gas outlet;
• and
• a gas supply system connected to the gas inlet, the gas supply system including:
• a first gas supply line connected between a process gas source and the gas inlet, the first gas supply line having an intermediate node;
• a second gas supply line connected between a purge gas source and the intermediate node;
• a first valve disposed upstream of the intermediate node on the first gas supply line;
• a second valve disposed upstream of the first valve on the first gas supply line;
• a first air supply line connected between an air source and the first valve, the first air supply line having a branch node;
• a second air supply line connected between the branch node and the second valve;
• a solenoid valve disposed upstream of the branch node on the first air supply line;
• and
• a controller to control the first valve and the second valve to open the first and second valves in a first mode for supplying a process gas from the process gas source to the substrate processing chamber, and close the first and second valves in a second mode for supplying a purge gas from the purge gas source to the substrate processing chamber,
• wherein the first and second valves are air operated valves, and
• the controller is configured to control the solenoid valve to open the solenoid valve in the first mode, and close the solenoid valve in the second mode.