Anisotropic broadening of Cu nanorods during glancing angle deposition

Regular arrays of freestanding Cu nanostructures were grown on patterned Si substrates using glancing angle deposition (GLAD) from two oppositely positioned sputtering sources. Continuous azimuthal substrate rotation during deposition leads to the formation of vertical 430-nm-wide rods, which broaden anisotropically during subsequent growth with a stationary substrate. Statistical analyses of plan-view micrographs combined with numerical simulations indicate a linear increase in the width aspect ratio with deposition time that is attributed to a change in the growth front direction. This technique, termed simultaneous opposite GLAD, provides a unique approach for nanostructure shaping. (c) 2006 American Institute of Physics.