Patent ID: 7253881
Filing Date: 2007-08-07
Classification: G03F

Abstract:
1. A lithographic apparatus comprising: an illumination system that conditions a radiation beam; an array of individually controllable elements that modulates a cross-section of the radiation beam; a substrate table that supports a substrate; a projection system that projects the modulated radiation beam onto a target portion of the substrate, the projection system including an array of focusing elements arranged in a plane such that each focusing element transmits a different part of the radiation beam onto a spot on the substrate; and a controller that controls elements within a group of a plurality of the individually controllable elements to direct part of the modulated radiation beam through a respective focusing element in the array of focusing elements, such that an exposure moment of the focusing element is maximized, wherein the exposure moment is defined by one of (a) the area of the focusing element traversed by the radiation beam, and (b) the area of the focusing element traversed by the radiation beam multiplied by the distance from the center of the focusing element summed over the focusing element.