Patent ID: 9358588
Filing Date: 2016-06-07
CPC Classification: B01F,B08B,C11D,H01L

Claim Text:
1. A substrate cleaning method comprising the steps of: immersing a substrate in a cleaning liquid contained in a cleaning tank and maintaining the substrate upstanding within the tank; generating ultrasonic waves in the cleaning liquid from below the substrate to clean the substrate, while supplying more cleaning liquid into the cleaning tank from below the substrate so that the cleaning liquid overflows from the tank through an open upper end of the tank, and taking out the substrate from the cleaning liquid contained in the cleaning tank after the step of generating ultrasonic waves, wherein, in the step of generating ultrasonic waves, a dissolved gas concentration of a gas dissolved in the cleaning liquid is lowered after a lapse of a certain time period from starting generation of ultrasonic waves, so that the step of generating ultrasonic, waves includes a step in which the ultrasonic waves are generated in the cleaning liquid when the cleaning liquid has a higher dissolved gas concentration and a succeeding step in which the ultrasonic waves are generated in the cleaning liquid when the cleaning liquid has a lower dissolved gas concentration.