Electron beam prepatterning for site control of self-assembled quantum dots

Abstract
A site-control technique for individual InAsquantum dots(QDs), formed by self-assembling has been developed, using scanning-electron-microscope assisted nanodeposition and metalorganic vapor phase epitaxy. We find that the nanoscale deposits, created at the focal point of the electron beam on a semiconductor surface, act as “nanogrowth masks”. Growth of a thin epitaxial layer produces nanoholes extending down to the deposits. The carbon deposits can be removed by oxygen plasma etching. When a compressively strained layer is deposited on this surface,QDs are self-organized at the hole sites, while no dots are observed in the flat surface region.