LITHOGRAPHIC PROJECTION APPARATUS, DIFFRACTION MODULE, SENSOR MODULE, AND METHOD OF MEASURING WAVE FRONT ABERRATION

摘要

PURPOSE: A measurement system is provided to measure the wave front aberrations in a lithographic projection apparatus. CONSTITUTION: A lithographic projection apparatus comprises: a radiation system for supplying a projection beam(PB) of radiation; a support structure for supporting patterning means, the patterning means serving to pattern the projection beam according to a desired pattern; a substrate table(WT) for holding a substrate; and a projection system(PL) for projecting the patterned beam onto a target portion of the substrate; characterized by: a measurement system for measuring wave front aberrations of the projection system, the measurement system comprising a grating that is movable into the projection beam between the radiation system and the projection system, and a pinhole arranged in a pinhole plate that is movable into the projection beam between the projection system and a detector for detecting light traversing the pinhole.