Patent ID: 7619722
Filing Date: 2009-11-17
Classification: G03F

Abstract:
1. A lens replacing method for replacing a predetermined lens having a non-zero refractive power in a projection optical system configured to project a pattern of an original body illuminated with exposure light onto a substrate, the lens replacing method comprising: mounting the predetermined lens in a first projection optical system; measuring a wavefront of measuring light passing through the first projection optical system including the predetermined lens to obtain a first measurement result; mounting a master lens corresponding to the predetermined lens in the first projection optical system; measuring a wavefront of measuring light passing through the first projection optical system including the master lens to obtain a second measurement result; installing the first projection optical system with the predetermined lens mounted therein into an exposure apparatus; mounting an alternative lens to the predetermined lens in a second projection optical system having the same specifications as those of the first projection optical system; measuring a wavefront of measuring light passing through the second projection optical system including the alternative lens to obtain a third measurement result; mounting the master lens in the second projection optical system; measuring a wavefront of measuring light passing through the second projection optical system including the master lens to obtain a fourth measurement result; processing the alternative lens in accordance with a difference obtained by determining a difference between the difference between the first and second measurement results and the difference between the third and fourth measurement results; removing the predetermined lens from the first projection optical system installed in the exposure apparatus; and mounting the processed alternative lens in the first projection optical system.