In-Situ Spectroscopy of Ion-Induced Photon Emission During Metal Nanoparticle Formation in Silica Glass with High-Flux Cu Implantation

Abstract

ABSTRACTIon-induced photon emission from a silica glass irradiated with high-flux Cu ions was measured in a wavelength range from 450 nm to 800 nm, while nanoyarticles spontaneously formed in the silica glass. Current density was varied up to 100 µA/cm2 at a constant total dose of 3×106ions/cm2. The photon emission primarily arose from the vicinity of the substrate surface and consisted of sharp peaks due to neutral and singly-ionized species, Cu(I), Cu(II) and Si(II) ions, as well as a broad-band background. Intensity of Si(II) and Cu(I) increased with increasing current density. On the other hand, Cu(II) did not show a monotonic increase, decreasing around 100 µA/cm2. Measurements of in-situ EDX and ex-situ RBS were also conducted to study the relevant mechanisms. The ion-induced photon emission was attributed to recombination processes of sputtered ions and electrons in the plasma, induced by the high-flux Cu beam.