Patent ID: 11880213
Assignee: TOKYO ELECTRON LIMITED
Field: Measurement (Instruments)
Classification: CPC G  B  H | IPC B  G  H

Claim 9:
10. A substrate liquid processing method, the method comprising:
regulating, by a valve mechanism, a flow of a processing liquid in at least one liquid pipe so that the processing liquid in the at least one liquid pipe connected to a discharge nozzle is located only upstream of a first pipe measurement site of the at least one liquid pipe; and
detecting, by a liquid detection sensor, presence or absence of the processing liquid at the first pipe measurement site located at a first measurement point,
wherein the at least one liquid pipe includes a supply line including the first pipe measurement site, and a drain line connected to the supply line and provided at a position lower than the discharge nozzle,
wherein the valve mechanism includes a supply opening/closing valve that regulates a flow of the processing liquid in the supply line, and a drain opening/closing valve that regulates a flow of the processing liquid in the drain line,
wherein when retracting the processing liquid to the upstream side of the first pipe measurement site, the drain opening/closing valve operates so as to flow the processing liquid from the supply line to the drain line,
wherein the liquid detection sensor includes a light receiving part capable of receiving detection light, and a light emitting part that emits the detection light,
wherein the at least one liquid pipe is provided to be movable relative to the liquid detection sensor so that the at least one pipe crosses an optical path of the detection light from the light emitting part to the light receiving part, and
wherein the presence or absence of the processing liquid at the first pipe measurement site is detected based on comparison between a magnitude of an amount of the detection light received by the light receiving part and a threshold value.