| 摘要 |
An EUV light source (2) serves for generating a used output beam (3) of EUV illumination light for a projection exposure apparatus for projection lithography. The light source (2) has an EUV generation device (2c), which generates an EUV raw output beam (30). The raw output beam (30) has a circular or elliptic polarization (31). A used polarization setting device (32) of the light source (2), for the purpose of setting the polarization of the used output beam (3), exerts on the raw output beam (30) an effect (34) which is linearly polarizing with regard to the direction of polarization. The used polarization setting device (32) has at least one phase retarding component (37) which is arranged in the beam path of the raw output beam (30). Said at least one phase retarding component generates a net phase shift between the two linearly polarized waves which are superimposed to form the polarization of the raw output beam (30), which net phase shift is less than half a wavelength λ of the used output beam (3) of the EUV illumination light. The result is an EUV light source having an improved output beam for resolution-optimized illumination. |
