Formation of Si nanocrystals in ion implanted Si-SiO₂structures by MeV electron irradiation

Abstract

Si nanoclusters generated in Si-SiO 2 structures implanted with different doses of Si ions S Kaschieva, A Gushterov, P Gushterova et al. were implanted in n-type Si-SiO 2 structures. The ion-beam energy was chosen so that the maximum number of the implanted ions would be deposited close to or at the Si-SiO 2 interface. The reference (non-implanted) and ion implanted samples were simultaneously irradiated by 20 MeV electrons with a flux of about 1×10 15 cm -2 . The MeV electron irradiation effect on the redistribution of the implanted ions in Si-SiO 2 structures was studied using RBS spectroscopy. The SiO 2 surface roughness changes induced by ion implantation and high-energy electron irradiation of the structures were observed by atomic force microscopy (AFM).

Influence of 20 MeV electron irradiation on the optical properties and phase composition of SiOx thin films

“…Investigations on 20 nm thick SiO 2 films have shown that the irradiation with 20-MeV electrons induced the formation of Si nanocrystals at fluences of 10 16 -10 17 el/ cm 2 . 22,23 In a previous investigation on 20-MeV electron irradiated homogeneous 200 nm thick silicon suboxide films (SiO x , x ¼ 1.3), we have found that the surface roughness of the film decreased, some structural changes in the oxide matrix took place, and a small amount of amorphous silicon phase appeared. 24 Further investigations by various complementary techniques will allow to get more information about the effect of the 20 MeV-electron irradiation on the phase separation and Si nanocluster formation processes in homogeneous SiO x films and the amount of the pure silicon phase and the size of nanoclusters in composite Si-SiO x films.…”

MeV Electron Irradiation of Ion-Implanted Si-SiO2 Structures

“…The shape and density of Si nanocrystals depend on the type of implanted ions. Si nanocrystals are created in SiO 2 of the implanted Si-SiO 2 structure after MeV electron irradiation only [8,9].…”