OPTICAL ELEMENT FOR A LITHOGRAPHIC APPARATUS LITHOGRAPHIC APPARATUS COMPRISING SUCH OPTICAL ELEMENT AND METHOD FOR MAKING THE OPTICAL ELEMENT

摘要

The lithographic apparatus includes an optical element comprising an oriented carbon nanotube sheet. The optical element has an element thickness in the range of about 20 to 500 nm and has a transmittance of at least about 20% for EUV radiation having a wavelength in the range of about 1 to 20 nm under vertical irradiation with EUV radiation. The oriented carbon nanotube sheet can be used essentially as an optical element and can be designed to reduce debris and / or improve the ratio of EUV / undesired radiation. The sheet does not necessarily require a support due to its strength. The optical element of the present invention may not be supported.;