Ron A. Synowicki, Greg K. Pribil, Gerry Cooney, Craig M. Herzinger & Steven E. Green, J.A. Woollam Co., Inc. 645 M Street, Suite 102, Lincoln, NE, USA, Roger H. French, Min K. Yang, M.F. Lemon, DuPont Co Central Research, E356-384, Wilmington, DE, USA, John H. Burnett & Simon Kaplan, National Institute of Standards and Technology, Atomic Physics Division, 100 Bureau Drive, Gaithersburg, MD, USA
ABSTRACT
As immersion lithography continues to develop at a rapid pace it will be necessary to determine the refractive index n and k of immersion fluids since the fluid becomes an important element of the optical system. The refractive index of several candidate immersion fluids for 193nm and 157nm immersion lithography is demonstrated using the prism minimum deviation technique. Measurements have been implemented on a commercially available variable-angle spectroscopicellipsometer system capable of operation into the vacuum ultraviolet. Results compare very well to high-accuracy reference measurements performed at NIST.