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

• Si nanodots are produced by low energy Ar+ beam sputtering of Si (1 0 0) at 75° incidence angle with simultaneous substrate rotation.
• The beam energy was varied from 100 to 600 eV, the current density from 280 to 1250 μA cm−2 and the rotation speed from 5 to 25 rpm.
• The morphological characteristics of the dot pattern were studied by AFM, while the microstructure and chemical composition of the dots were analyzed by TEM.
• The EDX analysis shows that the dots are not induced by metal impurities.

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.