Chemical bond manipulation for nanostructure integration on wafer scale

In this paper, we have briefly summarized our activity in the area of chemi cal bond manipulation for the integration of nanostructures on a full wafer scale. Chemical bond manipulation involves a judicious combination of surf ace phenomena: reactions or diffusion, and growth process such as molecular beam epitaxy (MBE). Here, we present our results on oxidation, metallizati on and nitridation and their role in the formation of nanostructures. We fi nd that oxygen changes the bonding partner from Ge to Si and this phenomeno n can be controlled by controlling the annealing temperature. We have emplo yed this phenomenon for the fabrication of novel, multiperiod Si/SiO2/Ge la yered structure which exhibits interesting light emitting properties. Furth er, by making use of selective diffusion of cobalt atoms through Ge layers it is possible to incorporate metallic features into Ge quantum dots. Moreo ver, it is possible to fabricate Si nanopillars through high temperature re action of nitric oxide. NO molecules dissociate on the surface,and nitrogen atoms thus produced form nitride islands. These islands act as protective masks for the etching of Si by the oxygen atoms, through the desorption of SiO species. Occurrence of these two simultaneous processes result in the f ormation of nanometre-sized Si pillars capped by silicon nitride. All these results emphasize the fact that we can extend information obtained through traditional surface science experiments for the fabrication of novel struc tures on a full wafer scale.