A SINGLE QUALITY FACTOR FOR ELECTRON BACKSCATTERING FROM THIN-FILMS

In this paper, Buckingham's theorem on physically similar systems is a pplied for the first time to the derivation of interpolation curves of numerical data. A simplified dependence of the curves on a limited nu mber of effective dimensionless parameters is found by a novel approac h. In particular, the method is applied to Monte Carlo modelling and t he calculation is considered of the backscattering coefficient eta fro m a general substrate in the elastic regime. A single dimensionless ba ckscattering parameter is introduced and a simple scaling law is deter mined, indicating how the configuration of the many variables involved can eventually change without affecting the result. The validity of t he law is demonstrated in the 5 to 100 keV energy range, with substrat e thicknesses ranging from 10 to 21000 angstrom and for all the substr ates of the periodic table.