Patent ID: 8570492
Filing Date: 2013-10-29
Classification: G03F

Abstract:
1. A lithographic apparatus comprising: a substrate table comprising a holder configured to hold a substrate in a holding plane; a projection system configured to project, when the substrate table is positioned in an exposure area, a patterned radiation beam onto a target portion of the substrate; a substantially vibration isolated frame supporting the projection system, a substrate table position measurement system configured to measure a position of the substrate table, wherein said substrate table position measurement system comprises a sensor frame mounted on a sub-frame of the lithographic apparatus and wherein the first sensor head is mounted on the sensor frame; a projection system position measurement system configured to measure a position of the projection system, the projection system position measurement system comprising a projection system reference element and a sensor assembly to determine a position of the sensor assembly with respect to the projection system reference elements, and wherein one of the sensor assembly and the projection system reference element is mounted on the projection system, and the other one of the sensor assembly and the projection system reference element is mounted on the sensor frame.