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 degrees C for 5 h) of the sapphire substrates with miscut angle of 0.3 degrees. 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 degrees) on the annealed sapphire substrates have shown homogeneous, uniform and isolated tungsten nanowires.