Patent ID: 9599904
Date: 2017-03-21
CPC Classifications: G03F

Claim:
1. A method of operating an illumination system of a microlithographic projection exposure apparatus, the illumination system configured to illuminate a mask positioned in a mask plane, the illumination system comprising a beam deflecting component that produces an intensity distribution in a pupil surface, the illumination system also comprising a beam deflection array of reflective or transparent beam deflecting elements, each deflecting element configured to illuminate a spot in the pupil surface having a position that can be varied by changing a deflection angle produced by the beam deflecting element, the method comprising: a) determining a target intensity distribution in the pupil surface of the illumination system; b) determining an arrangement of spots in the pupil surface that approximates the target intensity distribution determined in a); c) determining a function assigned to a beam deflecting element, the function describing a relationship between: i) positions of the spot illuminated by the beam deflecting element in the pupil surface; and ii) the deflection angle produced by the beam deflecting element when illuminating the light spots; d) determining deflection angles to obtain the arrangement of spots determined in c) by using the function determined in c); and e) supplying control signals to the beam deflecting elements such that the deflection angles determined in d) are produced.