Quantitative depth profiling of ultra-shallow phosphorus implants in silicon using time-of-flight secondary ion mass spectrometry and the nuclear reaction 31P(α,p 0) 34S

Abstract

Concentration profiles of ultra-shallow phosphorus implants in silicon have been extracted through use of time-of-flight SIMS in combination with nuclear reaction analysis. The phosphorus implants spanned the energy range 1–30 keV with fluences from 1e13 to 1e15 cm −2. The resonance in the nuclear reaction 31P(α,p 0) 34S at incident alpha particle energy 4.96 MeV was used to measure the total retained phosphorus for an implant fluence of 1e15 cm −2, hence quantifying the associated SIMS profile. For lower fluence implants, absolute profiles were recovered from the SIMS data by scaling the profile integrals. Over the implant energy and fluence ranges we have used we find no evidence for loss of phosphorus due to self-sputtering.