Dielectric function representation by B-splines

Accurate dielectric function values are essential for spectroscopic ellipsometry data analysis by traditional optical model-based analysis techniques. In this paper, we show that B-spline basis functions offer many advantages for param- eterizing dielectric functions. A Kramers–Kronig consistent B-spline formulation, based on the standard B-spline recursion relation, is derived. B-spline representations of typical semiconductor and metal dielectric functions are also presented. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)