Area-selective formation of Si nanocrystals by assisted ion-beam irradiation during dual-ion-beam deposition

We investigate the effect of Ar-ion-beam irradiation during the deposition of SiOx films by dual-ion-beam deposition system. Ion-beam irradiation effectively increases the oxygen content, x, in SiOx films indicative of the preferential sputtering of Si phase as compared to SiO2 phase in SiOx films. We observe the intense photoluminescence from nonirradiated sample after postdeposition annealing at 1100degreesC indicating the formation of Si nanocrystals as shown by a cross-sectional transmission electron microscope. However, the increased oxygen content in ion-beam-irradiated sample results in small optical volume of small Si nanocrystals not sufficient for yielding appreciable photoluminescence intensity after postdeposition annealing. The property is utilized for achieving the area-selective formation of Si nanocrytals by inserting a shadow mask in assist ion beam during deposition. (C) 2004 American Institute of Physics.