Lithographic apparatus with alignment subsystem, device manufacturing method using alignment, and alignment structure

摘要

A lithographic apparatus comprising an alignment subsystem (21) for aligning the substrate (W) on the substrate table (WT) relative to the patterning means (MA). The alignment structure (10) comprises a non-periodic feature (15) which is detectable as a capture position or a check position using a reference grating (26) in the alignment subsystem (21). The non-periodic feature (15) may cause a phase effect in the detected signal of the alignment subsystem (21) or an amplitude effect.