Secondary Dimer Ion Emission Probability in Sputtering Cu-Ni Alloy

For a quantitative determination of composition and local order structure of alloy surfaces using SIMS, relative intensities among various cluster ions and their influences by matrix effects have been analysed. Dimer formation yield is considered to reflect, to some degree, the atomic arrangement of surroundings, from the standpoint of either model that the dimer leaves the surface as an intact species or as a recombination product of monomers. In this paper, a systematic study of homo- and hetero-dimer emission yields is presented with our particular interests in the possible alloying effect and the concentration dependence of the yields. The secondary ion sampling depth of the sputtering technique is also discussed in comparison between AES and SIMS results.