Polarization evaluation mask, exposure device, and polarization evaluation method

An exposure device, comprising:

• a projection lens;
• and a polarization evaluation mask disposed upstream of the projection lens with respect to an illumination light thereof to evaluate a polarization state of the projection lens,
• the polarization evaluation mask including:
• a transparent substrate;
• a light shielding portion formed on the transparent substrate and having a plurality of openings therein;
• a plurality of quarter-wavelength plates formed to cover at least one of the openings, fast axes of the quarter-wavelength plates being different in azimuth by a certain angle;
• and
• a plurality of polarizers disposed upstream of the quarter-wavelength plates with respect to the illumination light and formed to overlay the quarter-wavelength plates and cover at least one of the openings/ transmission axes of the polarizers being different in azimuth by a certain angle,
• the plurality of openings being provided with different combinations of an azimuth of the polarizer and an azimuth of the quarter-wavelength plate from one another.

A polarization evaluation method of evaluating a polarization state of a projection lens of an exposure device, comprising:

• positioning a light shielding portion having an opening, a quarter-wavelength plate to cover the opening, and a polarizer to be overlaid on the quarter-wavelength plate from a downstream side of illumination light, at closer positions to the illumination light than the projection lens is;
• changing an azimuth of a fast axis of the quarter-wavelength plate and an azimuth of a transmission axis of the polarizer at predetermined angular intervals to generate plural combinations of the azimuths, and measuring an intensity of light obtained by letting the illumination light transmit through the polarizer under each of the combinations;
• and
• calculating a Mueller matrix based on the intensities.