Double EUV illumination uniformity correction system and method

摘要

A lithographic apparatus includes a uniformity correction system located at a plane and configured to receive a substantially constant pupil when illuminated with the beam of radiation. The uniformity correction system includes fingers that move into and out of intersection with a beam so as to correct an intensity of respective portions of the radiation beam. According to another embodiment, a method includes for: focusing a beam of radiation at a first plane to form pupil; adjusting the intensity of the beam near the first plane by moving fingers located near the first plane into and out of a path of the beam of radiation, wherein a width of a tip of each of the fingers is larger than that of corresponding actuating devices used to move each corresponding one of the fingers; patterning the beam; and projecting the patterned beam onto a substrate.

主权项

1. A lithographic apparatus comprising:
an illumination system configured to condition a beam of radiation, the illumination system comprising a uniformity correction system, the uniformity correction system including:
fingers configured to be movable into and out of an intersection with the radiation beam so as to correct an intensity of respective portions of the radiation beam, andactuating devices coupled to corresponding ones of the fingers and configured to move the corresponding fingers,wherein a width of a tip of each of the fingers is larger than that of a width of the actuating devices, the fingers are arranged in first and second groups in respective first and second planes that are separated from each other along a direction perpendicular to the planes, and the width of the tip of each finger is larger than a spacing between the fingers so that adjacent fingers overlap; a support structure configured to hold a patterning device, the patterning device configured to pattern the conditioned beam of radiation; a substrate table configured to hold a substrate; and a projection system configured to project the patterned radiation beam onto a target portion of the substrate.