AVS 52nd International Symposium
    Surface Science Wednesday Sessions
       Session SS1-WeM

Paper SS1-WeM7
Steering Induced Nanopatterning: Super Poisson Growth at Grazing Incidence

Wednesday, November 2, 2005, 10:20 am, Room 200

Session: Growth and Alloying of Surfaces
Presenter: H. Wormeester, University of Twente, The Netherlands
Authors: H. Wormeester, University of Twente, The Netherlands
F.L.W. Rabbering, University of Twente, The Netherlands
B. Poelsema, University of Twente, The Netherlands
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Analysis of high-resolution LEED data of 40 ML Cu on Cu(001) deposited at various polar angles led to the conclusion that attractive forces between the surface and the incoming particles have a dramatic steering effect on the trajectory of the particle. Incoming particles are attracted towards protruding structures leading to increased roughness and the formation of 1D nanopatterns at grazing incidence deposition. Already in the submonolayer coverage range consequences of the steering effect is observed for grazing incidence deposition. The steering induced heterogeneous distribution of the incoming flux has been modeled by a combination of long range Van der Waals forces and EAM calculations. The resulting trajectories have been combined with kMC simulations taking into account a large variety of intra and inter layer diffusion processes. The simulations are in good accordance with diffraction measurements up to 40 ML at both normal and grazing incidence. The evolution of the 1D nanopattern at glancing incidence deposition in terms of the distance between the ripples, the anisotropy and the roughness has been studied. The roughness evolves from a layer-by-layer fashion in the initial phase towards a strongly roughened interface above 10 ML. At 30 ML the roughness turns out to be even larger than for a Possion distribution, i.e. super Poisson growth is observed. The steering effect thus implies the necessity of a very different view for understanding the morphology development in growth at oblique incidence.