Patent ID: 7839480

Claim:
A method of exposing a photoresist layer on a substrate surface to ultraviolet light through a photomask, comprising: mounting a framed pellicle on the photomask, the framed pellicle comprising a pellicle frame and a pellicle membrane coupled to the pellicle frame, the pellicle frame having first and second apertures each communicating a first space surrounded by the photomask and the framed pellicle with a second space outside of the framed pellicle; and flowing gas from within the first space through the first aperture to outside the framed pellicle while simultaneously exposing the photoresist layer to ultraviolet light through the pellicle membrane and the photomask; wherein flowing gas from the first space through the first aperture to outside the framed pellicle comprises providing a tube external to the framed pellicle, the tube having an opening aligned with the first aperture such that a positive pressure gas flow through the tube creates a suction force urging gas out of the first space through the first aperture and the opening and into the tube.