Low Damage Etching of Polymer Materials for Depth Profile Analysis Using Large Ar Cluster Ion Beam

抄録

  In this study, we demonstrate low damage etching of polymer materials for depth profile analysis by using large Ar cluster ion beams. Recently, we have proposed to use keV-energy large cluster ions as primary ions for secondary ion mass spectrometry (SIMS). The intensities of molecular ions from the polymer films were kept constant after etching with large Ar cluster ions, though the primary ion fluence exceeded the static limit. These results prove that large cluster ion beam irradiation rarely leads to damage accumulation on the surface of the polymers, and these characteristics as etching beam could be also suitable for other depth profiling techniques. In addition, the surface chemical states of the polymers were measured with X-ray photoelectron spectrometry (XPS). The chemical states of the polymethyl methacrylate (PMMA) sample etched with Ar atomic ion beams differed significantly from those of the untreated sample, whereas the chemical states were maintained even after etching with large Ar cluster ion beams.