METHOD FOR OPERATING AN ILLUMINATION SYSTEM OF A MICROLITHOGRAPHIC PROJECTION EXPOSURE APPARATUS

摘要

A method of operating an illumination system of a microlithographic projection exposure apparatus is provided. A set of illumination parameters that describe properties of a light bundle which converges at a point on a mask to be illuminated by the illumination system is first determined. Optical elements whose optical effect on the illumination parameters can be modified as a function of control commands are furthermore determined, as well as sensitivities with which the illumination parameters react to an adjustment of the optical elements, induced by the control commands. The control commands are then determined while taking the previously determined sensitivities into account, such that deviations of the illumination parameters from predetermined target illumination parameters satisfy a predetermined minimisation criterion. These control commands are applied to the optical elements, before the mask is illuminated.

主权项

1. A method for setting an intensity distribution for a pupil of an illumination system of a microlithography tool, the method comprising:
measuring an initial intensity distribution for the pupil of the illumination system; determining variations between the initial intensity distribution and a target intensity distribution for the pupil, the variations being characterized by an intensity modulation and a distortion, the intensity modulation being expressed as a first combination of functions based on Zernike polynomials and the distortion being expressed by a second combination of functions; and adjusting at least one element in the illumination system to reduce the variations between the initial and target intensity distributions for the pupil.