Efficient n-type doping of Si nanocrystals embedded in SiO2 by ion beam synthesis

It is shown that co-implantation, with overlapping projected ranges of Si and P or As, followed by a single thermal annealing step is an efficient way to form doped Si nanocrystals (Si-nc's) embedded in SiO2 with diameters of a few nanometers. Atom probe tomography is used to image directly the spatial distribution of the various species at the atomic scale, evidencing that the P and As atoms are efficiently introduced inside the Si nanocrystals. In addition, we report on the influence of the dopant doses on the Si-nc's related photoluminescence as well as on the I(V) characteristics of MOS structures including these Si-nc's.