Ion beam synthesis of narrow Ge nanocluster bands in thin SiO₂ films

This paper reports on self-organization of narrow bands of Ge nanoclusters in thin thermally grown SiO₂ layers by means of ion beam synthesis. Although the implanted Ge profile is distributed over almost the whole SiO2, a delta-like nanocluster band very close to, but well separated from the Si/SiO₂ interface is formed under specific implantation and annealing conditions. The evolution of this band can be explained by a model taking into account collisional ion beam mixing and reactions near the Si/SiO₂ interface, which describes in good agreement the experimental results. The reliable fabrication of such cluster bands are the basis for new memory applications.