Directional growth of nanocrystalline Si nanorod array by mid-frequency magnetron sputtering

A new route to fast prepare well-aligned nanocrystalline Si nanorod array by mid-frequency (MF) magnetron sputtering was proposed in this study. Pulsed bias technique has been employed to adjust ion-bombardment condition over the growing film surface. For the Si samples deposited on the glass substrates with bipolar pulsed DC power supply, it was found that the two-dimensional growth mode of Si films was converted to the one-dimensional growth pattern at negative bias voltages no less than −60 V. The growth mode transition was ascribed to the coarsening of the growing surface in conjunction with atomic-scale shadowing effect. The nanocrystalline Si nanorods were also fabricated on stainless steel substrates successfully.