Time of flight secondary ion mass spectrometry study of silicon nanoclusters embedded in thin silicon oxide layers

Si nanoclusters have been formed by 5 keV Si1 implantation at a fluence of 131016 atoms/cm2 into a 200 Å thin thermally grown SiO2 film on Si ~100!, followed by thermal treatment at 1000 °C with different annealing times. All the annealed samples show a broad photoluminescence spectrum with increasing intensity as function of annealing time. The use of a dual beam time of flight secondary ion mass spectrometry in negative mode with Cs1 ions at low energy for sputtering allows us to observe variations in Si2 signal due to excess of silicon atoms introduced by implantation. With the high sensitivity achieved using this instrumental configuration it is possible to follow Sin2 signals which give information about the chemical enviroment of the Si atoms. The possibility of studying the time evolution of the nucleation and growth of nanoclusters has been investigated.