Illumination system with flat 1D-patterned mask for use in EUV-exposure tool

摘要

A catoptric system having a reference axis and including a reflective pattern-source (carrying a substantially one-dimensional pattern) and a combination of only three optical components disposed sequentially to transfer EUV radiation incident the first optical component onto the pattern-source. The combination is disposed in a fixed spatial and optical relationship with respect to the pattern-source, and represents an illumination unit (IU) of a 1D EUV exposure tool that additionally includes a projection optic sub-system configured to form an optical image of the pattern-source on an image plane with the use of only two beams of radiation. These only two beams of radiation originate at the pattern-source from the EUV radiation transferred onto the pattern-source.