Well-ordered arranging of Ag nanoparticles in SiO_2/Si by ion implantation

摘要

Well-ordered arrangements of Ag nanoparticles have been found for Ag-implanted SiO_2 at depths corresponding to the projected range and end of range of Ag ions. Thermally grown SiO_2 films of 300 nm thick on Si were implanted with 350keV-Ag ions to fluences of 0.37-1.2 × 10~(17) ions/cm~2 at a current density about 4μA/cm~2. 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 SiO_2/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.