Embodiments of the present invention generally provide an apparatus and methods for etching photomasks using charged beam plasma. In one embodiment, an apparatus for performing a charged beam plasma process on a photomask includes a processing chamber having a chamber bottom, a chamber ceiling and chamber sidewalls defining an interior volume, a substrate support pedestal disposed in the interior volume, a charged beam generation system disposed adjacent to the chamber sidewall, and a RF bias electrode disposed in the substrate support.