Processing liquid supply system and operation method thereof

An operation method comprising:

• providing a processing liquid supply system including;
• a tank configured to store a processing liquid supplied from a processing liquid supply;
• a circulation passage connected to the tank;
• a plurality of supply passages connected to the circulation passage and configured to supply the processing liquid to each of a plurality of liquid processing units that perform a liquid processing on a substrate;
• a first pump filter set that is a combination of a first pump and a plurality of first filters provided downstream of the first pump;
• and
• a second pump filter set that is a combination of a second pump and a plurality of second filters provided downstream of the second pump,
• wherein the first pump filter set and the second pump filter set are arranged in series in the circulation passage such that the first pump filter set is located upstream of the second pump filter set,
• wherein the processing liquid supply system further includes a first return passage branched off from the circulation passage at a first branching point set between the first pump filter set and the second pump filter set to return the processing liquid flowing through the circulation passage to the tank;
• at operation initiation of the processing liquid supply system, operating the first pump to create a first circulation flow of the processing liquid passing from the tank through the circulation passage, the first branching point, and the first return passage before returning to the tank;
• and then,
• while creating the first circulation flow, operating the second pump to flow the processing liquid to the circulation passage downstream of the first branching point as well.

An operation method comprising:

• providing a processing liquid supply system including:
• a tank configured to store a processing liquid supplied from a processing liquid supply;
• a circulation passage connected to the tank;
• a plurality of supply passages connected to the circulation passage and configured to supply the processing liquid to each of a plurality of liquid processing units that perform a liquid processing on a substrate;
• a first pump filter set that is a combination of a first pump and a plurality of first filters provided downstream of the first pump;
• and
• a second pump filter set that is a combination of a second pump and a plurality of second filters provided downstream of the second pump,
• wherein the first pump filter set and the second pump filter set are arranged in series in the circulation passage such that the first pump filter set is located upstream of the second pump filter set,
• wherein the circulation passage includes:
• a main passage section provided with the first pump filter set and the second pump filter set;
• and first and second branch passage section and a second branch passage section branched off from the main passage section, and the processing liquid discharged from the tank is configured to pass through the main passage section, then enter the first branch passage section and the second branch passage section, and return to the tank through the first branch passage section and the second branch passage section,
• wherein the processing liquid supply system further comprises a first on-off valve provided in the first branch passage section, a second on-off valve provided in the second branch passage section;
• at operation initiation of the processing liquid supply system, initiating an operation at a first set flow rate by the first pump while the first on/off valve is open and the second on/off valve is closed, and then, initiating an operation at a second set flow rate, equal to or less than the first set flow rate, by the second pump, thereby flowing the processing liquid through the first branch passage section, and then,
• while the first pump is operated at the first set flow rate and the second pump is operated at the second set flow rate, closing the first on-off valve and opening the second on-off valve, thereby flowing the processing liquid through the second branch passage section, and then, opening both the first on/off valve and the second on/off valve, thereby flowing the processing liquid through both the first branch passage section and the second branch passage section.