QUANTITATIVE DEPTH PROFILE ANALYSIS BY EPMA COMBINED WITH MONTE-CARLOSIMULATION

Calibrated x-ray intensities of arsenic and gallium, implanted with va rious ion-energies and doses into silicon, were measured over a wide r ange of electron-beam energies and angles of incidence. For the first time Monte-Carlo (MC) simulation was applied to evaluate the EPMA-data with respect to depth-profiles parameters, particularly at non-normal electron incidence. Accurate agreement between MC-simulated and measu red k-ratios was obtained in the whole range of excitation conditions applied. The resulting range parameters determined from the EPMA data agree closely with those obtained by other authors from RBS or NAA but like these they show systematic deviations from theoretical predictio ns. Actual measurements on samples implanted with 10(14) ions cm-2 cle arly prove the limits of detectability for As and Ga in Si to be below this number. Similar sensitivity was found for elements with atomic n umbers Z > 10 but for light elements (Z less-than-or-equal-to 10) the limit of detectability is increased by about one order of magnitude. P rovided the concentrations are appropriate, EPMA combined with MC-simu lation is a promising technique for the accurate quantitative, non-des tructive, and spacially resolved analysis of depth-profiles.