Interlayer atomic diffusion as the reason for self-assembled quantum dot formation Original Research Article

Self-assembled 3D-islands formation during epitaxial growth was investigated using a kinetic Monte Carlo model. Schwoebel barriers for the explanation of 3D growth kinetics were suggested. The diffusion hop probability ratio for atom hops up to hops down χ, leading to 2D, 3D and Stranski–Krastanov growth modes, was obtained. The necessity of atomic flow from the island edge to the upper layers for 3D-island formation was demonstrated. Island size equalization during the growth process was observed for certain χ values. The new layer nucleus on the top of the island becomes the trap for atoms detached from the edges of the lower layer. Atomic flow to the upper layer increases and that is the reason for the equalization of separate 3D-island lateral sizes.