Diameter control of gallium nitride nanowires

Gallium nitride GaN nanowires are grown with controlled diameter and position by combining electron-beam lithography and naturally occurring surface tension forces. Lithographically defined particle diameters were held constant while only the film thickness was varied. Annealing drives as-deposited metal disks toward hemispheres according to conservation of volume constraints, resulting in well-controlled catalyst particles with radii smaller than those of the as-deposited particles. Transmission electron microscopy and electron diffraction confirm that the nanowires are highly crystalline wurtzite GaN. The ability to structurally control the GaN nanowire size yields effective modulation of NW-FET conductivity. © 2007 American Institute of Physics. DOI: 10.1063/1.2728782