A study was made of the epitaxial growth of self-assembled Ge quantum dots when a sub-monolayer of C was deposited onto a Ge wetting layer prior to growth of the dots. Using atomic-force microscopy, combined with optical techniques such as Raman and ellipsometry, a systematic study was made of the effect of thermally activated Si interdiffusion upon dot density, composition and morphology, by changing only the growth temperature TWL of the wetting layer. Strikingly, it was observed that higher dot densities and a narrower size distribution were achieved by increasing the deposition temperature TWL, i.e. by enhancing Si interdiffusion from the substrate. A 2-stage growth procedure was suggested for fine tuning of the dot topography (density, shape and size).

Influence of Si Interdiffusion on Carbon-Induced Growth of Ge Quantum Dots - a Strategy for Tuning Island Density. A.Bernardi, J.O.Ossó, M.I.Alonso, A.R.Goñi, M.Garriga: Nanotechnology, 2006, 17, 2602-8