Regensburg 2010 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 40: Topical Session Growth Kinetics I

MM 40.2: Vortrag

Mittwoch, 24. März 2010, 16:30–16:45, H4

Rectangular mound formation and rotation during grazing incidence deposition of Cu/Cu(001) — •Herbert Wormeester, Raoul van Gastel, Frits Rabbering, and Bene Poelsema — Solid State Physics, MESA+ Institute for Nanotechnology, University of Twente, The Netherlands

We have studied the consequences of oblique incidence deposition for the morphology of the growth-front for a "prototypical" system Cu/Cu(001). Electron diffraction measurements and STM show that deposition at grazing incidence leads to the evolution of rectangular mounds, oriented perpendicular to the plane of incidence of the atom beam. At later stages, a transition towards rectangular mounds parallel to the plane of incidence is observed. To elucidate the mechanisms underlying the formation of anisotropic mounds and the rotation of the mounds, quantitative kMC simulations were performed, which support and predicted experimentally observed changes in mound orientation at later stages of growth. A close contact with experiment was established by using previously determined activation barriers for intra- and interlayer diffusion processes in the simulations. The latter describe accurately the observed morphologies in a wide range of temperatures (150-300 K) and coverages up to 40 ML. The simulations show that grazing incidence leads to a very rough growth front that can be characterized as Super Poisson roughening. The strongest roughening was found to occur just before the reorientation takes place. The layer distribution is also found to be markedly different from those obtained after normal incidence growth around this transition coverage.