Morphology modifications of quantum dots on Si(0Â 0Â 1) surface by ion sputtering

The evolution of the surface morphology of ordered, self-organized Ge nanodots samples by sputtering with various Ar+ ion energy and density has been investigated. Under low (300 eV) ion energy irradiation the surface smoothing mechanism dominates surface relaxation processes. The result indicates that ion sputtering with low ion energy can be utilized as an effective method for the preparation of ultra-smooth surfaces. In addition, with medium ion energy (650 eV) irradiation, the Ge nanodots transform into pure Si dots with the same shape characteristics as the unsputtered nanodots.