A method is provided for reducing the amount of film fragments discharged
into a processing liquid circulation system during removal of films from
wafers, thereby reducing the frequency of filter cleaning or filter
replacement. The method includes exposing a wafer containing a film
formed thereon in a process chamber of a substrate processing system to a
processing liquid, where the wafer is not rotated or is rotated at a
first speed and the processing liquid is discharged from the process
chamber to a processing liquid circulation system. Subsequently, exposure
of the wafer to the processing liquid is discontinued and the wafer is
rotated at a second speed greater than the first speed to centrifugally
remove fragments of the film from the wafer. Next, the wafer is exposed
to the same or a different processing liquid and the processing liquid is
discharged from the process chamber to a processing liquid drain.