Patent ID: 7019815
Filing Date: 2006-03-28
Classification: G03F

Abstract:
1. A lithographic projection apparatus comprising: a radiation system constructed and arranged to supply a projection beam of radiation; a first object table provided with a mask holder constructed and arranged to hold a mask; a second, movable object table provided with a substrate holder constructed and arranged to hold a substrate; a measurement station having a first position detection system configured to measure the position of said second object table at said measurement station; an exposure station having a projection system configured to image irradiated portions of the mask onto target portions of the substrate; a second position detection system configured to measure the position of said second object table at said exposure station; a first sensor at said measurement station, said first sensor being arranged to measure the position of the surface of the substrate in a first direction substantially perpendicular to the substrate surface; and a second sensor at said exposure station, said second sensor being arranged to measure the position of the surface of the substrate in said first direction.