Tungsten self-organization nanowires prepared by DC magnetron sputtering

Tungsten nanowires were deposited by DC magnetron sputtering onto vicinal sapphire substrates with a specific geometry in which the entrance angle (solid angle) of the vapor beam relative to the substrate was modified. Through 2D auto-correlation function analysis, suitable conditions to obtain a nanoscale corrugated surface with a high-order correlation were determined concerning the annealing procedure (1300 °C for 5 h) of the sapphire substrates with miscut angle of 0.3°. Depending on the entrance angle of the tungsten vapor beam, different nanoparticles and/or nanowires were systematically produced under controlled conditions. AFM images, from the samples deposited with an entrance angle lower or equal to the miscut angle (0.3°) on the annealed sapphire substrates have shown homogeneous, uniform and isolated tungsten nanowires.