Selective positioning of InAs quantum dots on a GaAs substrate directly patterned by using an atomic force microscope

A selective positioning technique for InAs quantum dots (QDs) on an atomic force microscope (AFM)-patterned GaAs substrate has been proposed and implemented. AFM direct patterning was used to generate various patterns having line widths of several tens of nanometers; then, InAs QDs were grown by using the metalorganic chemical vapor deposition technique. A nonuniform distribution of QDs was observed near the patterns, and the detailed shape of the QD distribution and the sizes of the QDs depended on the spacing and the width of the patterns. The growth condition for the case where the QDs could be aligned along the patterns was found in our work.