Cross-sectional TEM observation of copper-implanted SiO2 glass

Transmission electron microscopic observation has been made on SiO2 glass implanted to a dose of 6 × 1016 ions/cm2 at an energy of 160 keV and in a sample implanted to 6 × 1016 ions/cm2 at 169 keV and to 2 × 1016 ions/cm2 at 35 keV. In the sample with 6 × 1016 ions/cm2, the depth distribution of implanted Cu is bimodal in shape. It has been found that nano-sized particles of copper are formed in both depth regions of the bimodal distribution and the distribution of Cu colloid diameters has a shape that is close to that of implanted Cu concentrations. A triple layer of Cu colloid particles has been formed by sequential implantation using differing acceleration voltages (160 keV followed by 35 keV).