Quantitative depth profile analysis by EPMA combined with Monte-Carlo simulation

Calibrated x‐ray intensities of arsenic and gallium, implanted with various ion‐energies and doses into silicon, were measured over a wide range 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 measured 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 predictions. Actual measurements on samples implanted with 1014 ions cm−2 clearly prove the limits of detectability for As and Ga in Si to be below this number. Similar sensitivity was found for elements with atomic numbers Z > 10 but for light elements (Z ⩽ 10) the limit of detectability is increased by about one order of magnitude. Provided the concentrations are appropriate, EPMA combined with MC‐simulation is a promising technique for the accurate quantitative, non‐destructive, and spacially resolved analysis of depth‐profiles.