A few years ago we have started to use the emerging experimental technique of laterally resolved x-ray photoelectron spectroscopy  for the study of individual semiconductor nanostructures . The possibility to measure photoelectron spectra from objects as small as 40 nm has opened the door to detailed studies of intermixing and alloying which occur during the growth of semiconductor quantum dots. More recently, we have refined the analytical tools for this x-ray spectromicroscopy, which now provides a minimally intrusive elemental mapping of surfaces at the nanoscale and holds the promise of remarkable versatility. We have applied our procedure to the characterization of the two most prominent quantum dot model systems, namely InAs/GaAs  and Ge/Si , with the aim of investigating the surface stoichiometry gradients and gaining insight into the intermixing dynamics. By analysis of detailed surface compositional maps from individual nanometric islands we are able to associate alloying in these islands to surface transport processes .
1 Jan 2006
Volume: 2 Pages: 401