Controlled arrangement of self-organized Ge islands on patterned Si (001) substrates

We report the ability to arrange self-organized Ge islands on patterned Si (001) substrates. Selective epitaxial growth of Si is carried out with gas-source molecular beam epitaxy to form Si mesas followed by subsequent Ge growth. Self-aligned and regularly spaced Ge islands are formed on the 〈110〉-oriented ridges of the Si stripe mesas. A mono-modal size distribution of the islands has been observed on the ridges. Using preferential nucleation sites allows us to place Ge islands at predetermined positions. The controlled arrangement of self-organized nanostructures offers the potential applications of island arrays for the implementation in nanoelectronics and quantum computation.