Texture orientation of glancing angle deposited copper nanowire arrays

Self-assembled copper nanowires were deposited on native oxide Si(100) substrates using glancing angle deposition with and without substrate rotation. Wire morphology, texture and crystallographic orientation are strongly dependent on the deposition parameters. A method for determining the preferred crystal orientation is described. This orientation is found to be different from what is expected from the geometric orientation of the wires. For wires deposited without substrate rotation, the face-centered-cubic (fcc)(111) crystal orientation, which corresponds to the close-packed, low surface energy (111) plane of copper, lies between the long axis of the wire and that normal to the substrate. X-ray diffraction data show that the wires exhibit bundling behavior perpendicular to the plane of incidence. For samples deposited with azimuthal rotation of the substrate, the fcc(l 11) directions in the wires are evenly distributed in a cone around the long axis of the wires, which point normal to the substrate. When the substrate is rotated during deposition at an angle of 75degrees, the wires exhibit a strong fcc(220) texture, These observations show that wires deposited with substrate rotation are highly textured and have random orientations in the plane of the substrate. (C) 2004 American Vacuum Society.