Self-organized NC-layers by conventional ion implantation: status report WP2 - fundamental related experiments

The report describes the experimental proof of the formation of SiO2/Si-inteface near nanocrystal delta-layers in 500 nm thick silicon oxide due to interface mixing (defined displacement of matrix atoms) using Si irradiation through the SiO2 and Ge-implantation into the SiO2 without Ge deposition near the interface. Ge has been implanted for decoration of Si precipitates near the interface by Ge during thermal treatment of the ion irradiated SiO2.
RBS und XTEM investigations show that inteface near Ge-nanocrystal delta-layers are formed only in the case of ion beam mixing of the SiO2/Si-interface. The results agree with theoretical predictions done by Monte-Carlo computer simulations.
Furthermore, results of hydrogen depth profiling on Si-, Ge- and Sn-implanted SiO2-layers in the as implanted state using Nuclear Reaction Analysis (NRA) are reported. From H-depth profiling we conclude that in as implanted SiO2-layers a radiation defect enhanced water inward diffusion from moisture of the ambient atmosphere takes place. The absorbed H2O (H, OH) interfere the precipitation and Ostwald-Ripening of nanocrystals during thermal treatment, following the ion implantation process.