Patent ID: 11892776
Assignee: ASML NETHERLANDS B.V.
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 14:
15. A projection system for an extreme ultraviolet (EUV) lithographic apparatus, the projection system comprising:
a filter configured to suppress at least a zeroth order portion of a shaped EUV radiation beam, wherein an EUV radiation beam output from a source is shaped via one or more two-dimensional (2D) features of a patterning device to form the shaped EUV radiation beam; and
one or more reflective elements configured to direct an unsuppressed portion of the shaped EUV radiation beam towards a substrate to expose a radiation-sensitive portion of the substrate according to the one or more 2D features,
wherein at least one reflective element of the one or more reflective elements comprises an aperture to pass radiation therethrough, and
wherein the filter comprises the aperture and the aperture is arranged to receive therein the at least zeroth order portion, while directing the unsuppressed portion of the shaped EUV radiation beam towards the substrate, to enable suppression of the at least a zeroth order portion or the filter comprises a reflecting element to block the at least zeroth order portion, the reflecting element located in an optical path of the shaped EUV radiation beam from the at least one reflective element towards the substrate.