Sputtering yields of PMMA films bombarded by keV C60+ ions

A quartz crystal microbalance (QCM) has been used to determine total-mass sputtering yields of PMMA films by 1-16 keV C60+,2+ ion beams. Quantitative sputtering yields for PMMA are presented as mass loss per incident ion Ym. Mass-lost rate QCM data show that a 13 keV C60 cluster leads to emission equivalent to 800 PMMA molecules per ion. The power law obtained for the increase in sputtering yield with primary ion energy is in good agreement those predicted by “thermal spike” regime and MD models, when crater sizes are used to estimate sputtering.