Semiconductor wafer processing method

A wafer processing method in a processing apparatus including a processing chamber in which a wafer to be processed is located, a sample stage arranged inside the processing chamber and having an electrode configured to electrostatically adsorb the wafer, and a dispersion plate arranged above the sample stage opposite to an upper surface of the sample stage and having a plurality of through-holes through which electrically-charged particles of gas for processing the wafer flow into the processing chamber, wherein the plurality of through-holes are arranged in a ring-shaped region of the dispersion plate in an outer peripheral region thereof, the method comprising:

• a waferless electricity-removal step of removing an electric charge charged on the sample stage without placing a wafer on the sample stage by supplying the electrically-charged particles through the through-holes of the dispersion plate into the processing chamber;
• and
• a wafer processing step of electrostatically adsorbing the wafer placed on the sample stage and processing the wafer after the waferless electricity-removal step.