Patent ID: 6437858
Filing Date: 2002-08-20
Classification: G01M,G03F

Abstract:
An aberration measuring method comprising the steps of:providing an aberration mask comprising a plurality of aberration measuring patterns units each having a plurality of elemental patterns with a predetermined pattern width, the elemental patterns having a pattern length direction parallel to a given straight line, the aberration measuring pattern units being disposed in a given circumferential direction such that said straight line of each of the aberration measuring pattern units is cyclically shifted relative to a reference line at an angle of (&pgr;/2)/(2n+1) rad (n=natural number) in a range between 0 rad and &pgr;/2 rad; transferring pattern images of the aberration measuring mask onto a substrate to be processed, using an optical system; and detecting the transferred pattern image, thereby measuring an aberration in the direction of said reference straight line of the optical system.