Annealing behaviour of c-SiO2 implanted layer distributed with high density Ag nanoparticles

High volume density Ag nanoparticles embedded in c-SiO2 matrix have been prepared by Ag ion implantation at an energy of 200 keV and a current density of about 20 mu A/cm(2) to a nominal dose of 6.7 x 10(16) ions/cm(2) at RT. Bright-field transmission electron microscopy (TEM) image indicates that Ag nanoparticles show two groups of sizes: the larger diameter is about 25 nm and the smaller is less than 10 nm. RBS spectra show that the distribution of implanted Ag atoms is bimodal which is associated with the two groups of nanoparticles above. Thermal stability of the implanted layer which consists of Ag nanoparticles, dissolved Ag atoms and c-SiO2 matrix has been investigated by RBS, TEM and Raman spectroscopy. RES spectra prove that little migration of Ag atoms is found and Ag nanoparticles are considerably stable at 300 degrees C annealing. Though the obvious change in the distribution of Ag is observed at 400 degrees C annealing in RBS spectra, TEM image identifies that both the larger and the smaller Ag nanoparticles still exist at relatively stable state. Following 750 degrees C annealing, Ag atoms drastically move, and furthermore, the bimodal character of the distribution disappears. On the other hand, the amorphized SiO2 implanted layer recrystal after 300 degrees C, 400 degrees C annealing.