Germanium growth on nanopatterned surface studied by STM

International audienceA square surface nanopatterning is obtained by etching a buried dislocation network realised by a specific molecular bonding method. This template is used to organise the germanium quantum dot growth. The initial surface morphology as well as the quantum dot position and size are studied by scanning tunneling microscopy (STM). It is shown that the nanomesa roughness induces the dot nucleation, and therefore several dots (4–5) per mesa are obtained. These dots are coarsened to a single dot per mesa under ultra high vacuum annealing at 725 °C. Deep trenches between the mesas, controlled by the chemical etching solutions, prevent the formation of larger dots