Dense arrays of ordered GaAs nanostructures by selective area growth on substrates patterned by block copolymer lithography

GaAs has been selectively grown in a hexagonally ordered array of nanometer-scale holes with a density as high as ∼ 10¹¹/cm² by metalorganic chemical vapor deposition. This array of holes was created using block copolynier lithography, in which a thin layer of diblock copolymer was used as an etching mask to make dense holes in a 15-nm-thick SiN_χ film. These selectively grown nanoscale features are estimated to be 23 nm in diameter with narrow lateral size and height distributions as charaeterized by field-emission scanning electron microscopy and tapping mode atomic force microscopy. The narrow size distribution and uniform spatial position of the nanoscale dots we report offer potential advantages over self-assembled dots grown by the Stranski-Krastanow mode.