Glancing angle sputter deposited nanostructures on rotating substrates: Experiments and simulations

Ordered arrays of Si nanorods and nanospirals have been produced by ion beam sputter glancing angle deposition of Si on rotating substrates. The substrates were prepatterned with honeycomb and hexagonal-closed-packed arranged Au dots obtained by nanosphere lithography. The effects of template type, substrate rotational speed, height of the artificial Au seeds, and deposition angle theta of the incident flux on the growth of the Si nanostructures is examined. Especially for the deposition of Si on honeycomb templates at different deposition angles, it is shown that the structure of the growing film changes drastically. A continuous film with honeycomblike arranged hillocks on top is deposited at normal incidence. With increased theta, the structure shifts to almost dense films with a mesh of hexagonally arranged pores (theta=70 degrees). Finally, separated rodlike structures with triangular cross section are obtained under glancing angle conditions (theta=85 degrees). In addition, the structural evolution of the glancing angle deposited Si films is compared with oblique angle deposition three-dimensional Monte Carlo simulations. Furthermore, the effects of surface diffusion on the growth of spiral Si nanostructures on nontemplated substrates in experiment and simulation are compared and discussed. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.3018145]