The bombardment of a 26nm poly(methyl methacrylate) (PMMA) film has been studied as a model for depth profiling of polymeric samples using a newly developed C 60 + ion source. Experiments were conducted on a ToF-SIMS instrument equipped with C 60 + and Ga + ion sources. A focused dc C 60 + ion beam was used to etch through the polymer sample at specified time intervals. Subsequent spectra were recorded after each individual etching cycle using both C 60 + 20keV and Ga + 15keV ion beams at field-of-views smaller than the sputter area. PMMA fragment ion at m/z=69 and substrate Au m/z=197 were monitored with respect to primary ion doses of up to 10 14 ions/ cm 2 . Depth resolution as determined by the interfacial region is found to be about 14nm. A >10-fold increase in sputter yield for C 60 + ion bombardment over Ga + ions under similar conditions is observed from quartz crystal microbalance (QCM) measurements and our findings compare to enhanced SF 5 + cluster bombardment yields of organic species.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Physics and Astronomy(all)
- Surfaces and Interfaces
- Surfaces, Coatings and Films