Step&Scan systems are pushed towards low k₁ applications. Contrast enhancement techniques are crucial for successful implementation of these applications in a production environment. A NA - sigma - illumination mode optimizer and a contrast-based optimization algorithm are implemented in LithoCruiser in order to optimize illumination setting and illumination pupil for a specific repetitive pattern. Calculated illumination pupils have been realized using Diffractive Optical Elements (DOE), which are supported by ASML's AERIAL II illuminator. The qualification of the illumination pupil is done using inline metrology on the ASML Step & Scan system. This paper describes the process of pattern specific illumination optimization for a given mask. Multiple examples will be used to demonstrate the advantage of using non-standard illumination pupils.

Date Published: 28 May 2004
PDF: 11 pages
Proc. SPIE 5377, Optical Microlithography XVII, (28 May 2004); doi: 10.1117/12.544240

Published in SPIE Proceedings Vol. 5377:
Optical Microlithography XVII
Bruce W. Smith, Editor(s)