Lithographic apparatus and device manufacturing method

摘要

A lithographic apparatus having an optical column capable of creating a pattern on a target portion of a substrate is disclosed. The optical column may have a self-emissive contrast device configured to emit a beam, and a projection system configured to project the beam onto the target portion. The apparatus may also have an actuator to move the optical column or a part thereof with respect to the substrate. The apparatus may be constructed to reduce the optical effect of density variation in a medium around the moving part of the optical column on the beam.

主权项

1. A lithographic apparatus comprising:
a self-emissive contrast device configured to emit a beam; a projection system configured to project the beam along an optical path onto a target portion of a substrate, the projection system comprising an optical element; an actuator to move at least the optical element with respect to the substrate; a first surface facing and immediately adjacent a radiation receiving surface of the optical element and with respect to which the radiation receiving surface of the optical element is movable, the first surface not having optical power and at least partly overlying the radiation receiving surface; a second surface facing and immediately adjacent a radiation emitting surface of the optical element and with respect to which the radiation emitting surface of the optical element is movable; and a control system configured to cause the self-emissive contrast device to modulate emission of the beam during projection and to cause the actuator to move the optical element during projection in a direction transverse to the optical path of the beam with respect to the first and second surfaces.