MONTE-CARLO SIMULATION OF BACKSCATTERED ELECTRONS AND ENERGY FROM THICK TARGETS AND SURFACE-FILMS

Electron-matter interaction is described by a Monte Carlo procedure in which the mean free path is calculated by using a screened Rutherford formula, while energy loss is computed by using the Kanaya and Okayama semiempirical expression, Monte Carlo simulation results of the backscattering coefficient have been compared with the available experimental data. The examined energy range was 5-30 keV, the atomic number range was 4-92, and the tilt angle range was O-degrees-80-degrees. The agreement between simulated and experimental data is found to be excellent in the energy range 10-30 keV; also for 5 keV the agreement is very good when the atomic number is lower than 50. Then the mean backscattered energy was computed for bulk targets, unsupported thin films, and surface films.