Method of aligning a substrate, a computer program, a device manufacturing method and a device manufactured thereby

摘要

While the alignment beam is focused on a mark on the substrate table, the substrate table is moved substantially perpendicularly to the alignment beam. If the image of the mark moves relative to a reference mark, then the substrate and the alignment beam are not perpendicular. The mark on the substrate table is aligned to a plurality of reference marks. At least two substrate marks are then aligned with a single reference mark. Errors due to the inclination of the alignment beam are eliminated from the expansion and rotation values calculated for the substrate.