Patent ID: 11869780
Assignee: TOKYO ELECTRON LIMITED
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A substrate liquid processing apparatus, comprising:
a processing liquid storage unit configured to store a processing liquid therein;
a drain unit configured to drain the processing liquid from the processing liquid storage unit; and
a control unit configured to control the drain unit,
wherein the control unit is configured to perform a first control in a constant concentration period during which a concentration of the processing liquid in the processing liquid storage unit is regulated to a set concentration and a second control, including multiple steps, in a concentration changing period during which the concentration of the processing liquid in the processing liquid storage unit is changed,
an individual set concentration is set for each of the multiple steps, and
in the second control, the control unit is configured to:
compare a set concentration for a current step after concentration change in the concentration changing period with a set concentration for a preceding step before the current step, and
control the drain unit to start draining of the processing liquid, when the set concentration for the current step is determined to be lower than the set concentration for the preceding step.