Description
An approach to in-situ wavefront aberration measurement is explored. The test is applicable to sensing aberrations from the image plane of a microlithography projection system or a mask inspection tool. A set of example results is presented which indicate that the method performs well on lenses with a Strehl ratio above 0.97. The method uses patterns produced by an open phase figure1 to determine the deviation of the target image from its ideal shape due to aberrations. A numerical solution in the form of Zernike polynomial coefficients is reached by modeling the object interaction with aberrated pupil function using the nonlinear optimization routine over the possible deformations to give an accurate account of the image detail in 2-D. The numerical accuracy for the example below indicated superb performance of the chosen target shapes with only a single illumination setup.
Date of creation, presentation, or exhibit
5-12-2004
Document Type
Conference Paper
Department, Program, or Center
Microelectronic Engineering (KGCOE)
Recommended Citation
Lena Zavyalova, Anatoly Bourov, Bruce W. Smith, "Automated aberration extraction using phase wheel targets", Proc. SPIE 5754, Optical Microlithography XVIII, (12 May 2004); doi: 10.1117/12.606460; https://doi.org/10.1117/12.606460
Campus
RIT – Main Campus
Comments
Copyright 2005 Society of Photo-Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited.
Note: imported from RIT’s Digital Media Library running on DSpace to RIT Scholar Works in February 2014.