| 摘要 |
A method for setting an illumination geometry for an illumination optical unit for EUV projection lithography is disclosed. The method includes defining a desired illumination geometry, followed by varying tilting angles of individual mirrors of a facet mirror within one and the same individual-mirror group. In a first tilting position, the individual mirrors are assigned via a first group-mirror illumination channel to a first facet of a second facet mirror. In at least one further tilting position, the individual mirrors are assigned either via a further illumination channel to a further facet of the second facet mirror or to a switch-off illumination channel. The tilting angle variation is carried out until an actual illumination geometry corresponds to the desired illumination geometry within predefined tolerances. |
