Production of ordered and pure Si nanodots at grazing ion beam sputtering under concurrent substrate rotation

Hexagonal array of Si-nanodots is spontaneously generated by low energy Ar+ sputtering of a Si (1 0 0) surface at grazing incidence angle (75°) under continuous rotation of the substrate holder. The effects of rotation speed, beam current density and beam energy on the dot morphology are investigated by atomic force microscopy. The transmission electron microscopy of the dot microstructure shows that the dots are crystalline and are not induced by metal contaminants. Moreover, the dots are found to be capped by negligibly thin amorphous layer.