Size selected growth of nanodots: Ion beam assisted deposition and transition from 2D to 3D growth

The size selection in quantum dot growth can be controlled by using the ion beam assisted deposition (IBAD) technique, as is previously demonstrated in experiments. Especially, in Ge/Si growth IBAD enhances the 2D to 3D transition and results a narrow size distribution compared to conventional deposition. We study size selection under IBAD using a continuous growth model with size dependent kinetics and thermodynamics. We show that ion beam assisted deposition exhibits stationary state of growth with uniform quantum dot size distributions. Finally we compare the results with nucleation theoretical predictions.