Lithography system for processing a target, such as a wafer, a method for operating a lithography system for processing a target, such as a wafer and a substrate for use in such a lithography system

Lithography system for processing a target, such as a wafer, the target comprising a target surface with a target position mark provided thereon, the lithography system comprising:

• a beam source arranged for providing a patterning beam, preferably light beam or a charged particle beam, such as an electron beam;
• a final projection system arranged for projecting a pattern on the target surface with said patterning beam,
• a chuck arranged for supporting the target;
• an actuator system arranged for moving the chuck in at least one dimension with respect to the final projection system;
• and,
• a mark position system arranged for detecting a position mark on a surface, such as the target position mark on the target surface;
• wherein the mark position system comprises at least one alignment sensor, the at least one alignment sensor comprising:
• a light source arranged for providing an alignment light beam;
• a light intensity detector arranged for determining a light intensity of a reflected alignment light beam, wherein the reflected alignment light beam is generated by reflection of the alignment light beam on said surface;
• and,
• an optical system arranged for focusing the alignment light beam on the surface and for guiding the reflected alignment light beam on the light intensity detector.