QUANTITATIVE-ANALYSIS OF SPUTTERED SPECIES

Species sputtered from a solid by ion bombardment are partly collected into a tantalum cell held at 3000 K where they are dissociated and ionized according to the Saha-Langmuir equation. A filament stretched through the cell and negatively biased with respect to the cell wall allows the atoms to be ionized by electron impact when the thermal process becomes inefficient. Ions produced either by the thermal process or electron impact are extracted from the cell and mass analyzed. The composition of the solid is determined from ion intensities after calibration of ionization coefficients. If has been demonstrated that the method has an absolute quantitative character. Applications to elemental quantitative analysis, high temperature studies of absorbat-surface chemical reactions and studies of sputtering phenomena are being presented.