Diaphragm for an integrator unit

摘要

The invention relates to a diaphragm (1) for an integrator unit of a microlithographic projection exposure system. The diaphragm (1) includes a diaphragm opening (3), which is symmetrical with respect to a first axis of symmetry (5). The widths of the diaphragm aperture (3) in the direction of the axis of symmetry (5) are dependent on the distance (y) from the first axis of symmetry (5). The widths are greater than or equal to the width at y=0. The diaphragm (1), together with a cylindrical integrator, forms an integrator unit, which is located in an illumination system.