In-situ spectroscopy of ion-induced photon emission during metal manoparticle formation in silica glass with high-flux Cu implantation

摘要

Ion-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 nanoparticles spontaneously formed in the silica glass. Current density was varied up to 100 mu A/cm~2 at a constant total dose of 3x10~(16) ions/cm~2. 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 broda-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 mu A/cm~2. 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 highflux Cu~- beam.