Depth profiles of Ag/Si(111) thin‐film interface regions

Abstract

AbstractThe metal/semiconductor interface region of in situ deposited Ag thin films prepared on a Si(111) substrate has been investigated using AES sputter depth profiling in conjunction with proton‐induced x‐ray emission (PIXE). Interface regions have been modeled with the interface analysis program LOGIT, developed at the National Institute of Standards and Technology (NIST). Values for the parameters obtained from this model indicate that the rate of ion beam sputtering through samples prepared without simultaneous low‐energy ion activation tended to be noticeably greater than the rate of sputtering through samples prepared with simultaneous ion activation. Further, we found that one effect of the ion beam is temporarily to shift the fractional Ag surface coverage to higher values. The likely mechanism for this shift is sputter redeposition by the ion beam of Ag atoms from large nucleated Ag islands, transporting them to open areas between islands. These results support conclusions from an earlier study, which found that the effect of low‐energy simultaneous ion beam activation during thin‐film deposition was to shift the mode of growth of Ag on an Si(111) substrate from an SK (layer‐plus‐island) to an FM (layer) growth mode, to a degree dependent on the conditions of simultaneous ion co‐bombardment.