Critical height and growth mode in epitaxial copper nanowire arrays fabricated using glancing angle deposition

The growth and resulting crystallography of Cu nanowire arrays fabricated using glancing angle deposition are studied. On native oxide Si(100), the nanowires exhibited a strong (110) texture for a deposition angle θ=75° with rotational symmetry of the low energy Cu[111] about the long axis. On hydrogen-terminated Si(110), the wires are epitaxial with the substrate. The critical height for epitaxial growth is maximal at θ=35°, and decreases rapidly with increasing deposition angle. Based on the growth mechanisms in glancing-angle-deposited materials, the theory of growth mode in epitaxial thin films, and the observations about texture formation in epitaxial and nonepitaxial Cu nanowires; we discuss the observed growth modes in epitaxial nanowire arrays.