a reticle having a pellicle frame and pellicle membrane is cleaned without removing or damaging the pellicle membrane . a cover encases the pellicle membrane and pellicle frame , sealing the pellicle from the external environment during a cleaning process . the cover fits around the periphery of the pellicle frame and covers the pellicle membrane . an edge of the cover in contact with the reticle forms a seal . the reticle is fastened to reticle supports on a spin chuck during the cleaning process . an anchor plate presses the cover to the reticle , maintaining the pellicle sealed from the external environment . the cover and reticle are sandwiched together between the anchor plate and spin chuck .