Imaging via zeroth order suppression

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.

A projection system for incorporation within a lithographic apparatus configured to project, via a radiation beam, a pattern of a patterning device onto a substrate, wherein the patterning device is configured to shape the radiation beam in accordance with the pattern, the projection system comprising:

• a filter configured to:
• suppress a zeroth order portion of a shaped radiation beam, and
• suppress interference between certain first order portions of the shaped radiation beam,
• wherein at least an unsuppressed first order portion of the shaped radiation beam is directed towards a substrate to form an image on the substrate, and
• wherein the projection system is configured to perform 2D interferometric printing by optical interference using the one or more two-dimensional (2D) features.