Patent ID: 9110387
Filing Date: 2015-08-18
Classification: G03F

Abstract:
1. A lithographic apparatus comprising: a support constructed to support a patterning device, the patterning device being capable of imparting a radiation beam with a pattern in its cross-section to form a patterned radiation beam; a substrate table constructed to hold a substrate; a positioner constructed to position the substrate table; a projection system configured to project the patterned radiation beam onto a target portion of the substrate, a substrate surface actuator arranged to face a part of a surface of the substrate facing the projection system, the substrate surface actuator configured to exert a force on the part of the surface of the substrate, the substrate surface actuator comprising a Lorentz actuator, and a position controller configured to control a position of the substrate table, the position controller being operably connected to the positioner and the substrate surface actuator to drive the positioner and the substrate surface actuator, the substrate surface actuator being driven, in use, by said controller to reduce, with said exerted force, an inaccuracy of positioning of the substrate surface with respect to a plane of focus of the projection system, and wherein the actuator is arranged to engage at least part of a zone of the surface of the substrate that surrounds a downstream lens of the projection system, seen along a direction of an optical axis of the downstream lens of the projection system.