Self-assembled NiSi quantum-dot arrays on epitaxial Si_0.7Ge_0.3 on (001)Si

The self-assembled NiSi quantum dot arrays were grown on relaxed epitaxial Si_0.7Ge_0.3 on(001)Si. The formation of the one-dimensional ordered structure is attributed to the nucleation of NiSi nanodots on the surface undulations induced by step bunching on the surface of SiGe film owing to the miscut of the wafers from normal to the (001)Si direction. The two-dimensional pseudohexagonal structure was achieved under the influence of repulsive stress between nanodots. Since the periodicity of surface bunching can be tuned with appropriate vicinality and misfit, the undulated templates promise to facilitate the growth of ordered silicide quantum dots with selected periodicity and size.