Method and apparatus for foam-assisted wafer cleaning

A foam-assisted wafer-cleaning and drying method and apparatus based on forming a funnel-shaped space between the base plate of the apparatus and the wafer to be cleaned and supplying a foam cleaning liquid to the aforementioned space through the central opening of the base plate for displacing the cleaning liquid foam consisting of a plurality of bubbles from the center of the wafer toward the wafer periphery with a constant speed of movement of the bubbles provided by gradually decrease of distance from the base plate to the wafer in the radial outward direction from the center of the wafer. The nanoparticles of contaminants are caught with a surface-tension force developed by bubble meniscuses on the wafer surface.