Method for improved lithographic patterning utilizing optimized illumination conditions and high transmission attenuated PSM
Method for improved lithographic patterning utilizing optimized illumination conditions and high transmission attenuated PSM
United States Patent 7,523,438
Hsu , et al.
April 21, 2009
Inventors: Hsu; Michael (Taipei, TW), Hsu; Stephen (Fremont, CA), Laidig; Thomas (Point Richmond, CA), Van Den Broeke; Douglas (Sunnyvale, CA), Chen; Jang Fung (Cupertino, CA)
Assignee: ASML Masktools B.V. (Ah Veldhoven, NL)
Appl. No.: 11/108,665
Filed: April 19, 2005
Abstract
A method for optically transferring a lithographic pattern corresponding to an integrated circuit utilizing a high transmission attenuated phase-shift mask onto a semiconductor substrate by use of an optical exposure tool. The method comprising the steps of generating a diffraction pattern corresponding to the lithographic pattern, where the diffraction pattern indicates a plurality of spatial frequency components corresponding to the lithographic pattern; determining which of the spatial frequency components need to be captured by a lens in the optical exposure tool in order to accurately reproduce the lithographic pattern; determining a set of illumination conditions required for the optical exposure tool to capture the spatial frequency components necessary for accurately reproducing the lithographic pattern; and illuminating the high transmission attenuated phase-shift mask with this set of illumination conditions.
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