Cross calibration of secondary ion mass spectrometers

Abstract

It is known from previous round-robin experiments that relative sensitivity factors, obtained on identical samples by different SIMS instruments, frequently disagree by a factor of up to 50. A method is suggested for cross-calibrating instruments in such a way that relative elemental sensitivity factors determined on one SIMS instrument may be used on another instrument for quantification of unknown samples. The method consists in actively tuning the operating parameters of instruments in such a way that relative sensitivity factors for B and W (with respect to Fe) in a homogeneous B/sub 15/Fe/sub 75/W/sub 10/ metallic glass sample (primary calibration standard, PCS) are in close agreement on all participating instruments. In an experimental in which this cross-calibration strategy has been adopted, relative sensitivity factors of seven further elements, determined on seven different SIMS instruments (including ion microscopes, ion microprobes, and quadrupole-SIMS), agree within a factor of the order of 1.7. Improvements may be expected with better tuning to the PCS. 11 references, 3 figures, 8 tables.