A method and apparatus for improving the uniformity of exposure of a periodic pattern

A method for improving the uniformity of exposure of a first periodic pattern in a photomask by a collimated beam in a photolithographic system using the Talbot effect to print a second periodic pattern into a photosensitive layer on a substrate in proximity to the photomask, the method comprising:

• a) providing a plate composed of a material transparent to the beam, the plate having opposing surfaces being mutually parallel and separated by a thickness;
• b) placing the plate in the photolithographic system such that the beam illuminates the plate at an initial angle of incidence and a beam transmitted by the plate illuminates the photomask;
• and
• c) rotating the plate through at least one angle about at least one axis of rotation during the exposure such that the transmitted beam displaces translationally across the photomask.

An apparatus for improving the uniformity of exposure of a periodic pattern in a photomask by a collimated beam in a photolithographic system using the Talbot effect to print a second periodic pattern into a photosensitive layer on a substrate in proximity to the photomask, the apparatus comprising:

• a) a plate composed of a material transparent to the beam, said plate having mutually parallel opposing surfaces separated by a thickness;
• b) said plate being placed in the photolithographic system such that the beam illuminates said plate at an initial angle of incidence and a beam transmitted by said plate illuminates the photomask;
• and
• c) said plate being rotated through at least one angle about at least one axis of rotation during the exposure such that the transmitted beam displaces translationally across the photomask.

A method for improving the uniformity of exposure of a first periodic pattern in a photomask by a collimated beam of monochromatic light in a photolithographic system printing a second periodic pattern into a photosensitive layer on a substrate in proximity to the photomask, the method comprising:

• a) providing a plate composed of a material transparent to the beam, the plate having opposing surfaces being mutually parallel and separated by a thickness;
• b) placing the plate in the photolithographic system such that the beam illuminates the plate at an initial angle of incidence and a beam transmitted by the plate illuminates the photomask;
• and
• c) rotating the plate through at least one angle about at least one axis of rotation during the exposure such that the transmitted beam displaces translationally across the photomask.

An apparatus for improving the uniformity of exposure of a first periodic pattern in a photomask by a collimated beam of monochromatic light in a photolithographic system printing a second periodic pattern into a photosensitive layer on a substrate in proximity to the photomask, the apparatus comprising:

• a) a plate composed of a material transparent to the beam, said plate having opposing surfaces being mutually parallel and separated by a thickness;
• b) said plate being placed in the photolithographic system such that the beam illuminates said plate at an initial angle of incidence and a beam transmitted by said plate illuminates the photomask;
• and
• c) said plate being rotated through at least one angle about at least one axis of rotation during the exposure such that the transmitted beam displaces translationally across the photomask.