Abstract: An optical mask has a first pellicle attached. The optical mask is inspected with the first pellicle in place using first wavelengths of electromagnetic radiation. The first pellicle is replaced with a second pellicle. The first pellicle only allows the first wavelengths of electromagnetic radiation to pass, and the second pellicle allows second wavelengths that are shorter than the first wavelengths to pass. A photoresist is exposed using the optical mask with the second pellicle in place. The second pellicle is replaced with the first pellicle. The optical mask is again inspected with the first pellicle in place using the first wavelengths of electromagnetic radiation.

Abstract: Disclosed is a photolithography (e.g., extreme ultraviolet (EUV) photolithography) system that incorporates a photomask-pellicle apparatus with an angled pellicle. The apparatus includes a photomask structure and a pellicle structure that is mounted on the photomask structure. The pellicle is essentially transparent to a given-type radiation (e.g., EUV radiation), is essentially reflective to out-of-band (OOB) radiation, and is positioned at an angle relative to the photomask. When radiation is directed toward the photomask-pellicle apparatus during a photolithographic exposure process, beams that are reflected and diffracted off of the patterned surface of the photomask structure are directed toward a target semiconductor wafer and beams that are reflected and diffracted off of the pellicle are directed away from the target semiconductor wafer. Aiming the OOB radiation away from the target semiconductor wafer improves imaging quality by minimizing the negative impact of OOB radiation.

Abstract: An optical mask has a first pellicle attached. The optical mask is inspected with the first pellicle in place using first wavelengths of electromagnetic radiation. The first pellicle is replaced with a second pellicle. The first pellicle only allows the first wavelengths of electromagnetic radiation to pass, and the second pellicle allows second wavelengths that are shorter than the first wavelengths to pass. A photoresist is exposed using the optical mask with the second pellicle in place. The second pellicle is replaced with the first pellicle. The optical mask is again inspected with the first pellicle in place using the first wavelengths of electromagnetic radiation.