Lithographic apparatus, aberration detector and device manufacturing method

摘要

An aberration detector for a lithographic apparatus is used. An imaging device captures an image of at least one pinhole feature of a target projected onto the imaging device by the projection system of the lithographic apparatus at two different locations separated in a direction parallel to the optical axis of the projection system. A controller obtains a representation of the aberration of the projection system from the captured images.

主权项

1. A lithographic apparatus, comprising:
a support configured to support a patterning device; a substrate table configured to support a substrate; a projection system configured to project an image of a patterning device supported by the support onto a substrate supported on the substrate table; and an aberration detector configured to measure an aberration of the projection system, wherein the aberration detector comprises:
a target supported by the support comprising a pinhole feature;an imaging device supported by the substrate table, configured to capture an image of the pinhole feature projected by the projection system;an actuator, configured to move the imaging device in a direction parallel to the optical axis of the projection system between a first position and a second position; anda controller configured to obtain respective images of the pinhole feature projected by the projection system from the imaging device in the first position and the second position and to obtain a representation of the aberration of the projection system from the respective images.