Abstract: A pellicle for isolating a photomask pattern from particulate contaminants. The pellicle includes a peripheral frame having at least one vent for the passage of a gaseous substance between the interior of the frame and the atmosphere outside of the frame. The vent is configured for removal of particulate contaminants from the gaseous substance before the gaseous substance flows into the interior of the frame. The vent includes a recess formed in a first edge of the frame and at least two inlets opening into the recess, one of which couples the recess to the interior cavity of the pellicle and the other of which couples the recess to the atmosphere outside of the frame. At least one inlet is located in the first edge of the frame.

Abstract: An optical pellicle and method of forming an optical pellicle. The pellicle includes a membrane and an anti-reflective coating covering at least one of the membrane surfaces. The membrane has a wavelength transmission pattern with consecutive first and second maximum transmission peaks where the first maximum transmssion peak corresponds to a wavelength of 365 nm and the second maximum transmission peak corresponds to a wavelength of 436 nm. The pellicle transits at least 99 percent of light striking said pellicle having a wavelength of about 361 nm to 369 nm and at least 99 percent of light striking said pellicle having a wavelength of about 430 nm to 442 nm. In one embodiment, the anti-reflective coating includes at least one intermediate layer having a refractive index less than the refractive index of the membrane, and an outer layer having a refractive index less than the refractive index of the intermediate layer.