Fabrication of nanoperiodic surface structures by controlled etching of dislocations in bicrystals

A method for the fabrication of periodic arrays of surface features with controlled spacings of 2–100 nm has been developed. This process relies on the selective etching of dislocations formed at a twist–bonded interface in a bicrystal. The production of nanoscale periodic silicon surface features with a mean spacing of 38 nm is reported. The etch rate of edge and screw dislocations is compared, and the rate of dislocation etching is found to be poorly correlated to strain. This observation calls long-held theories of dislocation etching into question.