Date of Award
1996
Degree Type
Dissertation
Degree Name
Doctor of Philosophy
Abstract
Quantitative analysis of homogeneous bulk unknowns using an electron probe microanalyzer requires the accurate knowledge of the depth distributions of x-ray production ({dollar}\phi{dollar}({dollar}\rho{dollar}z) curves). Straight line behaviour is observed in the plot of ln{dollar}\phi{dollar}({dollar}\rho{dollar}z) versus ({dollar}\rho{dollar}z){dollar}\sp2{dollar} for most experimentally measured data. Monte Carlo calculations can be used to simulate {dollar}\phi{dollar}({dollar}\rho{dollar}z) curves. However, ln {dollar}\phi{dollar}({dollar}\rho{dollar}z) versus ({dollar}\rho{dollar}z){dollar}\sp2{dollar} plots of these {dollar}\phi{dollar}({dollar}\rho{dollar}z) curves, in general, are nonlinear and concave downward. By introducing the concept of electron straggling into a multiple scattering Monte Carlo model, agreement with the behaviour of experimental curves is achieved.;Electron probe microanalysis can also be used for the characterization of thin films on substrates. The multiple scattering Monte Carlo program was used to simulate more than 300 thin film {dollar}\phi{dollar}({dollar}\rho{dollar}z) curves with different film/substrate combinations. The simulations were made at normal electron incidence in the energy range from 10-30 keV. Using these data and based on the concept of the ratio of {dollar}\phi{dollar}({dollar}\rho{dollar}z) values from the thin film to the corresponding bulk {dollar}\phi{dollar}({dollar}\rho{dollar}z) value at the same thickness, general equations were developed which allow prediction of thin film {dollar}\phi{dollar}({dollar}\rho{dollar}z) curves for any film/substrate combination at any electron energy. The equations can used with any bulk {dollar}\phi{dollar}({dollar}\rho{dollar}z) model. Comparisons were made with literature values of measured k-ratios in order to confirm the validity of the present model.
Recommended Citation
Chan, Ka Shing, "Simulation And Modelling Of Thin Film Phi(rho-z) Curves For Electron Probe Microanalysis" (1996). Digitized Theses. 2609.
https://ir.lib.uwo.ca/digitizedtheses/2609