Analysis of Surface Morphology and Chemical Composition of Silicon Implanted with Copper Ions

Abstract

We report on the results of analysis of the structure and chemical composition of the surface of c-Si single crystal substrates implanted with Cu+ ions with energy of 40 keV and doses in a range of 3.1 × 1015–1.25 × 1017 ions/cm2 for a current density of 8 μA/cm2 in the ion beam. It has been established using scanning electron microscopy and probe microscopy combined with X-ray photoelectron and Auger spectroscopy that at the initial stage, the implantation with Cu+ ions to a dose of 6.25 × 1016 ions/cm2 induces the formation of Cu nanoparticles with an average size of 10 nm in the Si surface layer. Upon a further increase in the implantation dose, beginning with 1.25 × 1017 ions/cm2 and higher, the nucleation of the η phase of copper silicide (η-Cu3Si) is observed. This is due to heating of the surface layer of the Si substrate during its irradiation to a temperature facilitating the formation of the η-Cu3Si phase.