Patent 7958899 was granted and assigned to Dainippon Screen Mfg Co on June, 2011 by the United States Patent and Trademark Office.
At a vibration applying position, ultrasonic vibration is applied upon a liquid film which is on a surface of a substrate. Concurrently with this, at a drop arrival position which is different from the vibration applying position, drops of a cleaning liquid are supplied to the liquid film, whereby wave-generating vibration which is different from the ultrasonic vibration is applied upon the liquid film. This dramatically improves removal of particles adhering to the surface of the substrate as compared with mere application of ultrasonic vibration. Hence, even when the output, the frequency and the like of the ultrasonic vibration are set to such an extent not damaging the substrate, it is possible to effectively remove particles with the wave-generating vibration and favorably clean the surface of the substrate.