Effect of indentation and annealing on 2 MeV Cu ion-implanted SiO2

Enhancement of surface plasmon resonance (SPR) in optical absorption has been found on Cu ion-implanted SiO2 substrate modified by micro-indentation and post annealing. The SiO2 was firstly implanted with 2 MeV Cu2+ ions, at an ion flux of 4 mu A/cm(2), up to a fluence of 6 x 10(16) ions/cm(2) at room temperature. After the ion implantation, dot-array patterns of micro-indents were made by a micro-Vickers machine, and annealed at 600 degrees C, 700 degrees C and 800 degrees C in vacuum for 1 h. The optical absorption spectra of the indented region and the non-indented flat region were measured by a dual beam spectrometer. After post annealing at different temperatures, all the indented areas showed higher absorbance of SPR at 2.2 eV, comparing to the flat region annealed under the same annealing conditions. In particular, the SPR enhancement reached maximum after 600 degrees C annealing, and decreases with further increasing annealing temperature. The result of SPR enhancement by the micro-indentation suggests that the indentation-induced deformation enhances the atomic migration, resulting in promoting the precipitation under thermal annealing. (c) 2007 Elsevier B.V. All rights reserved.