Abstract: In semiconductor manufacturing, a pellicle film (28) is used to protect the surface of a reticle (24). The reticle (24) is used in an optical microlithography system (10) to pattern semiconductor wafers (18). To work properly, the pellicle (28) must be transparent at the particular wavelength of light used to expose photoresist through the reticle (24). The pellicle (28) is made more transparent to short wavelength light used by the optical microlithography system by removing unwanted hydrogen in the pellicle (28). The unwanted hydrogen is removed by exposing the pellicle (28) to a gas containing fluorine. This unwanted hydrogen apparently came as artifacts of the process of the making the pellicle (28), particularly the chemicals introduced to terminate the polymerization process and the ones used as solvents.