COLLOID FORMATION EFFECTS ON DEPTH PROFILE OF IMPLANTED AG IN SIO2 GLASS

Ag+ ions of 150 keV were implanted into SiO2 glasses at room temperatu re to doses of 0.1-60 x 10(16)/cm2. Formation of Ag colloids in SiO2 g lasses was observed by the cross-sectional transmission electron micro scopy and optical absorption spectra. An anticorrelation is found betw een the Ag colloid size and the width of the Ag depth profile measured by Rutherford backscattering spectrometry. At low dose, the size of A g colloids is small (< 10 nm in diameter) and the Ag depth profile is close to that of a simulation calculation. At increasing dose, small A g colloids and/or Ag atoms aggregate to grow up to approximately 40 nm and the width of the Ag depth profile is reduced to approximately 50 nm, which is close to the above colloid size, indicating that the size of a Ag colloid particle controls the Ag depth profile. The size and shape of colloids are the keys which modify the optical properties by metallic ion implantation for applications such as optical isolators.