Calibration correction of ultra low energy SIMS profiles based on MEIS analyses for arsenic shallow implants in silicon

Abstract

Secondary ion mass spectrometry (SIMS) and medium energy ion scattering (MEIS) have been applied to the characterization of ultra shallow distribution of arsenic in silicon obtained by ion implantation at 0.5–5 keV. MEIS offers the advantage of accurate quantification and ultimate depth resolution <1 nm but the detection limit achievable is always poorer than the one obtained by SIMS. The comparison of the results obtained by the two techniques allows to discriminate among different SIMS quantification processes in order to individuate the best in terms of accuracy in the initial transient width and at the SiO 2–silicon interface and develop quantitative model for SIMS profiles to align them to the curves as determined by MEIS. This model relies on different sputtering condition in SiO 2 (such as sputtering rate and ion yield) and additionally compensates analysis behavior in SiO 2/Si interface.