The advantages of normal incidence ultra-low energy secondary ion mass spectrometry depth profiling

Using a boron multi-delta layer structure, we explore the use of ultra-low energy primary ion beams for secondary ion mass spectrometry (SIMS) analysis under various experimental conditions (different primary beam energies, beam incident angles and the use of oxygen flooding during profiling). To characterize the effect of the micro-roughening which occurs at non-normal incidence on the recorded depth profiles, we calculated the full width half maximum (FWHM) of the profiled delta layers and found that the combination of ultra-low energy and normal incidence provides constant and high depth resolution throughout the measured depth range. (C) 1999 Elsevier Science B.V. All rights reserved.