We studied growth and morphology of Al on Si(100) for submonolayer coverage and different substrate temperatures. At room temperature the Al atoms form short chains (several Al dimers long), which tend to branch.
We identified 3 types of the Al dimers: dark, dim and bright. Experiments conducted at 115 K showed strong anisotropy of surface migration of single Al atoms.
We used a statistical analysis of recorded motion of single atoms to estimate heights of diffusion barriers.