Characterization of periodic extreme ultraviolet multilayer based on multi-objective evolutionary algorithm.

Autor: Shang-qi Kuang, Xue-peng Gong, Hai-gui Yang
Předmět:
Zdroj: Journal of Applied Physics; 11/14/2017, Vol. 122 Issue 18, p1-7, 7p
Abstrakt: In order to refine the layered structure of extreme ultraviolet multilayers, a multi-objective evolutionary algorithm which is post-hybridized with the standard Levenberg-Marquardt algorithm is applied to analyze the grazing incidence X-ray reflectivity (GIXR) and the normal incidence extreme ultraviolet reflectance (EUVR). In this procedure, the GIXR data and EUVR data are simultaneously fitted as two objectives, and the high sensitivities of these two sets of data to layer thicknesses and densities are combined. This set of mathematical procedures is conducive to obtain a more correct model of periodic multilayers which can simultaneously describe both GIXR and EUVR measurements. As a result, the layered structure of Mo/Si multilayers with a period of about 7.0 nm is obtained. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index