Cluster primary ion bombardment of organic materials

In order to evaluate their potential for molecular surface analysis, we applied monoatomic (Ga, Cs, Au, Bi) as well as polyatomic (SF5, Aun, Bin, C60) primary ions to a series of organic samples. For the model system Irganox 1010 on LDPE we determined the secondary ion yield, the disappearance cross section and the resulting ion formation efficiency as a function of the primary ion energy. As a general result the efficiency is improved with the mass of the monoatomic primary ion. A further increase is obtained by the use of polyatomic primary ions. According to this, highest efficiencies are obtained for C60, the lowest for Ga. Additionally, molecular imaging was performed on real world samples (electronic components, pharmaceuticals): for this a cluster LMIS operated with Ga, AuGe or Bi was applied. The results reveal the potential of cluster SIMS to overcome existing limitations and to establish TOF-SIMS for new applications in the fields of polymers, biology and medicine. # 2004 Elsevier B.V. All rights reserved