Method and equipment for cleaning photoetching mask plate

The invention relates to a method and equipment for cleaning a photoetching mask plate. The method comprises the following steps: placing the photoetching mask plate to be cleaned in a cavity of plasma equipment; the plasma equipment is provided with a radio frequency power supply for generating plasma; inert gas is introduced into the cavity; the inert gas is helium and/or helium-hydrogen mixed gas; and keeping the temperature of the inert gas in the cavity to be lower than 50 DEG C, so that the inert gas generates plasma and acts on the photoetching mask plate. The plasma of helium and/or helium-hydrogen mixed gas is used for bombarding impurity ions on the photoetching mask plate, so that chemical bonds of the impurity ions are broken and converted into gaseous or water-soluble organic matter impurities, and the organic matter impurities can be simply removed subsequently. In the cleaning process, the special compound oxide layer, the absorption layer and the protection layer structure on the surface of th