Patent ID: 7619718

Claim:
A purge device for actively purging a pellicle volume enclosed within a reticle-pellicle assembly, the reticle-pellicle assembly having a reticle with a bottom portion, a pellicle, and a gas permeable pellicle frame, the gas permeable pellicle frame supporting the pellicle at a standoff from the reticle, the purge device comprising: a base having a purge input interface and a cavity, and at least one plate within the cavity of said base and extending parallel with the pellicle such that a gap region is formed between a surface of said at least one plate and said pellicle; said at least one plate including a pressure balancing plate having a set of holes; wherein said base includes one or more support members having an adjustable height that extend within said cavity to form a first plenum below said set of holes in said pressure balancing plate; wherein said cavity is configured to receive at least a portion of the reticle-pellicle assembly including a pellicle and the enclosed pellicle volume such that a first region within the cavity is formed at the purge input interface, a second region within the cavity is formed at a permeable side of the pellicle frame away from the first region, and said gap region is formed between the pellicle and a surface of the cavity, and purging gas sent through the purge input interface is kept at a higher pressure in the first region relative to the second region such that the purging gas flows through the enclosed pellicle volume and said gap region, whereby, a displacement force on the pellicle due to a pressure difference between purging gas in the enclosed volume and purging gas in the gap region is within a tolerance range of the pellicle.