Quantitative SIMS measurement of high concentration of boron in silicon (up to 20 at.%) using an isotopic comparative method

Highly boron doped (up to 20 at.%) silicon samples have been analysed by SIMS with the aim of quantifying the boron concentration in a range where the dilute regime may not be valid any more. An original method is used based on the simultaneous analysis of two different isotopes, namely image and image, in order that the known concentration of the first isotope (initially present with a far lower, constant concentration) is the basis of the quantification of the concentration of the second, present with a very high dose. Argon and oxygen beams have been used and conclusions are drawn about the presence of matrix effects in the case of the analysis of highly doped samples. It appears that only the use of a 8 keV image beam leads to a significant matrix effect, whereas it is nearly absent in the case of an analysis under 8 keV Ar+ beam. The proposed method may be applied to any element showing at least two isotopes in any binary alloys under any primary beam.