Pellicle is a thin film that protects reticle surface from particles in the air or other source of contaminations. Furthermore it makes particles on pellicle surface be out of focus to prevent wafer pattern distortion.
Membrane is attached to the anodized aluminum frame and then firmly attached to reticle.

General structure of Pellicle


Comparison of Pellicle Membranes

Material Perfluoro polymer Cellulose
Applied exposure wavelength KrF (193nm) i-, g-, h- line (365nm~436nm)
Transmittance ≥99% ≥99%
Uniformity of TR ≤0.2% ≤0.5%
integrated exposure energy Avg. 500,000J/cm2 Avg. ≥400,000J/cm2
shot number of exposure
500,000,000mj/cm2÷ 400mj/cm2
= 1,250,000shots
400,000,000mj/cm2÷ 400mj/cm2
= 1,000,000shots