Patent ID: 6704089
Filing Date: 2004-03-09
Classification: G03F

Abstract:
A lithographic projection apparatus comprising:a radiation system constructed and arranged to supply a projection beam of radiation; a support structure constructed and arranged to support beam patterning structure, the beam patterning structure serving to pattern the projection beam according to a desired pattern; a substrate table constructed and arranged to hold a substrate; a projection system constructed and arranged to project the patterned beam onto a target portion of the substrate; and an alignment system to align the substrate to the beam patterning structure, said alignment system comprising: an excitation source for directing electromagnetic radiation to a surface of said substrate so as to induce a wave therein in a region of an at least partially buried substrate alignment mark; and a measurement system to direct a measurement beam to be reflected by said surface and to detect surface effects caused by said wave thereby to perform an alignment to said substrate alignment mark.