Concentration profiles of Zn ions implanted with 60 keV for nanoparticle formation in silica glass

Surface recession due to sputtering under low-energy and high-fluence heavy-ion implantation makes shallower and broader depth profile of implanted ions than those calculated by conventional ion-range simulation-codes such as SRIM. Depth profiles of Zn atoms in silica glasses NOD implanted with Zn(+) ions of 60 keV up to 1.0 X 10(17) ions/cm(2) were evaluated using both experimental methods as Rutherford backscattering spectrometry (RBS), sputtering depth-profiling by X-ray photoelectron spectroscopy (XPS), and an advanced numerical simulation code TRIDYN, which includes the sputtering loss effects. The TRIDYN code predicts the shallowing of the projectile range from similar to 46 to similar to 27 nm with increasing the fluence up to 1 X 10(17) ions/cm(2), and very high-concentration (similar to 20 at%) of Zn atoms close to the surface. However, RBS and XPS results exclude such high concentration close to the surface. These results suggest remarkable redistribution of Zn atoms from the nearer surface to the deeper region during the implantation. In fact, Zn-atom concentration near the surface and that near the projectile range are, respectively, lower and higher than those by the SRIM code predictions. (c) 2005 Elsevier Ltd. All rights reserved.