Open AccessComa measurement of projection optics in lithographic tools based on relative image displacements at multiple illumination settings
Author(s) -
Quanzi Yuan,
Xiangzhao Wang,
Zicheng Qiu,
Fan Wang,
Mingying Ma,
Le He
Publication year - 2007
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.15.015878
Subject(s) - coma (optics) , optics , distortion (music) , projection (relational algebra) , lithography , aerial image , physics , materials science , computer science , image (mathematics) , artificial intelligence , optoelectronics , amplifier , cmos , algorithm
In this paper, we propose a novel method for measuring the coma aberrations of lithographic projection optics based on relative image displacements at multiple illumination settings. The measurement accuracy of coma can be improved because the phase-shifting gratings are more sensitive to the aberrations than the binary gratings used in the TAMIS technique, and the impact of distortion on displacements of aerial image can be eliminated when the relative image displacements are measured. The PROLITH simulation results show that, the measurement accuracy of coma increases by more than 25% under conventional illumination, and the measurement accuracy of primary coma increases by more than 20% under annular illumination, compared with the TAMIS technique.