ILLUMINATION SYSTEM WITH CURVED 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 two optical reflectors disposed sequentially to transfer EUV radiation incident onto the first optical component to the pattern-source the substantially one-dimensional pattern of which is disposed in a curved surface. In one case, such combination includes only two optical reflectors (each may contain multiple constituent components). 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—includes a projection optical 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.