QUANTITATION OF MAJOR ELEMENTS WITH SECONDARY-ION MASS-SPECTROMETRY BY USING M-2(-MOLECULAR IONS())

A new quantitation method, based on the detection of M-2(+) molecular ions, is presented. It has been shown that M-2(+) molecular ions are f ormed by a recombination process between independently sputtered M and M+ particles. Based on this formation mechanism, it will be demonstra ted that M-2(+) molecular ions can be used to quantitate major element s. The method will be used for quantitation of an AlxGa1-xAs multilaye r. Furthermore, it will be shown that some matrix effects can be expla ined by the energy dependence of instrument transmission. (C) 1998 Ame rican Society for Mass Spectrometry.