Sputtering of the redeposited material was experimentally studied with the use of test structures specially prepared by the focused beam of gallium ions with different energies. The consequent milling of the structures and their characterization utilizing transmission electron microscopy revealed that the milling rate for the redeposited material is 1.3 times higher than for crystalline silicon. The dynamic Monte-Carlo simulations of sputtering were performed with the introduced discrete-continuous variation model for the surface binding energy of the silicon atoms, which takes into account the formation of the gallium precipitates in the surface layer of the bombarded material. The calculations allowed obtaining not only the correct values of redeposited material milling rate, but also the distributions of gallium atoms in the sputtered materials which were in the qualitative agreement with the experimental data.
Read full abstract