Controlled surface nanopatterning with buried dislocation arrays

Self-assembled configurations of nanostructures are expected to play an increasing role in devices design, as an alternative to conventional microelectronics. The key limitation is the lack of control on localisation, density and size uniformity of the structures. Here we show how to create a template to overcome these problems. A periodic nanometre scale patterning can be induced at a silicon surface by buried dislocation networks obtained by twist wafer bonding, using stress selective etching of the surface. These templates are morphologically characterised by scanning tunnelling microscopy and grazing incidence X-ray diffraction. Stress fields and elastic energy densities are calculated for the non-etched solid, and the selective etching mechanisms are discussed. Germanium growth experiments on such a Si patterned surface give a demonstration of the ordering efficiency. This study provides a general method to create a template, which organises nanostructures with controlled periodicity over the full size of a Si wafer.