Illumination apparatus with a high laser damage threshold and pattern transfer apparatus comprising the same

摘要

Illumination apparatus are disclosed for directing a laser beam or other light flux onto a target. The apparatus controls the polarization direction of the laser beam or other light flux with retarders in order to increase the damage resistance of the reflective coatings of the illumination apparatus. In addition, methods are disclosed for improving the damage resistance of reflective coatings used on optical elements of, e.g., a pattern transfer apparatus for projecting patterns from a reticle onto a substrate.