Projection lens is an important part of the lithography. The wave aberration is the key index, which directly affects the critical dimension. The main methods of wavefront aberration detection are shear interferometry, Shack- Hartmann diffraction interferometry method and point diffraction interferometry. One shearing interference method can realize the nanometer precision. This method needs high precise motion positioning and high signal-to-noise ratio of image acquisition system. a kind of image acquisition and motor positioning control system based on shear interference was designed and realized the high precision motion position of shear grating and shearing interference fringes of synchronization acquisition. a method of improving the shearing interference image imaging quality was proposed to improve the detection precision of the wave aberration, the simulation and experiment show that wave aberration precision can reach 10 nm; At the same time, through optimizing software algorithm, greatly improve the detection time and work efficiency.

Date Published: 24 March 2017
PDF: 6 pages
Proc. SPIE 10147, Optical Microlithography XXX, 1014720 (24 March 2017); doi: 10.1117/12.2257455

Published in SPIE Proceedings Vol. 10147:
Optical Microlithography XXX
Andreas Erdmann; Jongwook Kye, Editor(s)