Patent ID: 6295122
Filing Date: 2001-09-25
Classification: G03F

Abstract:
An illumination system for microlithographic projection equipment comprising in the listed sequencea light source,a first plurality of optical elements,a reticle masking system,a second plurality of optical elements defining a first lens group,a pupil plane,a third plurality of optical element defining a second lens group,a fourth plurality of optical elements defining a third lens group,a reticle plane,wherein said first plurality of optical elements collects light of said light source and illuminates said reticle masking system,wherein said first second and third lens group and said pupil plane define a REMA objective,wherein said REMA objective forms an image of said reticle masking system on said reticle plane,wherein said image has a distortion, andwherein a first optical path between two of said optical elements of said third lens group is adjustable to adjust said distortion.