Comparison of misalignment modes associated with metrology data nd projection-camera performance can be used to increase the sensitivity of metrology measurements to specific camera-performance specifications such as chief-ray distortion. Selection of measurable misalignment modes in the case of metrology and interesting misalignment modes in the case of camera performance is based on a determination of whether a mode can 'fit' into a projection camera given actuator-stroke and mirror tilt bounds. Measurement and interest subspaces are next compared using distance between subspaces. As an example of this type of analysis, we find that exit-pupil wavefront measurements can be made more sensitive to chief-ray distortion if these measurements are collected at field positions outside the ring field of view of an EUVL projection camera.

Date Published: 25 June 1999
PDF: 6 pages
Proc. SPIE 3676, Emerging Lithographic Technologies III, (25 June 1999); doi: 10.1117/12.351141

Published in SPIE Proceedings Vol. 3676:
Emerging Lithographic Technologies III
Yuli Vladimirsky, Editor(s)