OPTICAL ELEMENT FOR THE REFLECTION OF UV RADIATION, METHOD FOR MANUFACTURING THE SAME AND PROJECTION EXPOSURE APPARATUS COMPRISING THE SAME

摘要

The invention relates to an optical element (1a, 1b) for the reflection of UV radiation at an operating wavelength below 250 nm, preferably at 193 nm, comprising: a substrate (2a, 2b), a reflective layer (3a, 3b) made of aluminum superimposed on the substrate (2a, 2b), the reflective aluminum layer (3a, 3b) not being transparent to UV radiation. The reflective aluminum layer (3a, 3b) is (111)-plane oriented, and the reflective optical element (1a, 1b) has a reflectivity of more than 85 %, preferably of more than 88 %, more preferably of more than 92 %, in at least a range of incident angles of 10°, preferably of 15°, at the operating wavelength. The invention also relates to an optical element having a reflective layer made from a material having a higher melting point than aluminum, to methods for producing such optical elements, and to optical arrangements comprising such optical elements.