C60 cluster ion bombardment of organic surfaces

This paper reviews the results obtained with a C60-based ion beam system developed for routine application in ToF-SIMS analysis of organic materials. The bombardment of some representative organic materials by C60þ results in yield enhancements of at least 30–100-fold as compared to yields observed under Gaþ bombardment at the same energy. The total ion yields for C60þ are in the order of 1–10%. High molecular-weight polymers and monolayer molecular solids are damaged at about the same rate as under Gaþ bombardment. Thick films of molecular solids show 100 times less damage than Gaþ, such that essentially zero damage sputtering is possible, offering the possibility of analysis well beyond the static limit. The resulting efficiencies are greater than other polyatomic primary ions such as Au3þ or SF5þ and >103 for Gaþ. C60þ delivers no more molecular fragmentation than any other primary projectile used in SIMS. Some results on biological test samples to access the potential of the C60þ as a primary ion beam in bio-system analysis are reported. A brief discussion on a possible mechanism for ion enhancement by C60þ is presented. # 2004 Elsevier B.V. All rights reserved