SA step growth mechanism on (0 0 1) surfaces of diamond structure crystals

Abstract

SA step growth mechanism of (0 0 1) surfaces of diamond structure crystals was investigated by means of quantum chemical calculations. Adatoms migrating on dimer rows on the terrace become stationary at the down side of SA steps, because of the high potential energy wall preventing the adatoms running up the SA steps. Thus, migrating adatoms have a higher probability of remaining at the down side of SA steps than at any point of the terrace. The second adatom running down the SA step or migrating on the same dimer row of the lower terrace has a high probability of meeting the first adatom remaining at the down side of the SA step, and a new dimer is formed. It was concluded that the SA step growth is a complex event; i.e., the formation of an isolated dimer at the SA step is followed by SB step growth starting from the newly produced dimer as the smallest nucleus. The SB step growth progressing along the SA step means one step propagation of the SA step growth.