Alignment Marks or Alignment Mark Assemblies Measurement Methods, Alignment Systems and Lithography Tools

摘要

The present invention provides a method of measuring an alignment mark or alignment mark assembly, wherein the alignment mark comprises grid features extending in at least two directions, the method comprising the use of an expected position of the alignment mark or alignment mark assembly for alignment measuring the mark or alignment mark assembly, determining a first position of the alignment mark or alignment mark assembly in a first direction, determining a second position of the alignment mark or alignment mark assembly in a second direction; wherein the second direction is perpendicular to the first direction, determining a second direction scan offset between the determined second position and an expected position of the alignment mark or alignment mark assembly in the second direction, and a first correction position calibrating the first position based on the second directional scan offset using at least one set of calibration data to provide