Well-ordered arranging of Ag nanoparticles in SiO2/Si by ion implantation

Well-ordered arrangements of Ag nanoparticles have been found for Ag-implanted SiO2 at depths corresponding to the projected range and end of range of Ag ions. Thermally grown SiO2 films of 300 nm thick on Si were implanted with 350 keV-Ag ions to fluences of 0.37–1.2 × 1017 ions/cm2 at a current density about 4 μA/cm2. Cross-sectional transmission electron microscopy and scanning transmission electron microscopy reveal the presence of a two-dimensional array of Ag nanoparticles of 25–40 nm in diameter located at a depth of ∼130 nm, together with the self-organization of δ-layer of tiny Ag nanoparticles aligned along the SiO2/Si interface. X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) confirm the stability of these Ag nanoparticles against oxidation and sulfidation when stored in ambient air for 19–21 months.