Processing liquid supply device, processing liquid supply method, and storage medium

A processing liquid supply device of supplying a processing liquid to a target substrate held on a substrate holder, the processing liquid supply device comprising:

• a processing liquid supply mechanism including a flow rate control mechanism configured to be controlled based on an operation amount to adjust a flow rate of the processing liquid supplied from a processing liquid source, which stores the processing liquid therein, and a supply nozzle configured to discharge the processing liquid whose flow rate is adjusted by the flow rate control mechanism toward the substrate held on the substrate holder;
• a flow rate detection unit configured to detect the flow rate of the processing liquid supplied to the supply nozzle;
• a system identification unit configured to determine a system parameter based on a sum of product values obtained by multiplying the system parameter to each of a time-series sample value of the operation amount and a time-series sample value of the flow rate detected by the flow rate detection unit, in order to identify a system model for acquiring an estimated flow rate of the processing liquid discharged from the supply nozzle;
• and
• a flow rate controller configured to determine the operation amount by using the system parameter determined by the system identification unit and output the determined operation amount to the flow rate control mechanism,
• wherein the flow rate control mechanism is a flow rate control valve configured to increase or decrease the flow rate of the processing liquid according to an opening degree of a valve body, and
• the flow rate controller determines the operation amount, which is the opening degree of the valve body, based on a target flow rate of the processing liquid discharged from the supply nozzle and the system parameter determined by the system identification unit.