Berlin 2015 – wissenschaftliches Programm

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DS: Fachverband Dünne Schichten

DS 19: Ion and electron beam induced processes

DS 19.5: Vortrag

Mittwoch, 18. März 2015, 11:00–11:15, H 2032

Modelling ion-induced pattern formation based on theories of erosion and mass redistribution using the crater function formalism — •Hans Hofsäss — II. Physikalisches Institut, Universität Göttingen, Göttingen, Germany

The Bradley-Harper (BH) and Carter-Vishnyakov (CV) theories with their recent extensions [1,2] are evaluated with regard to a quantitative prediction of ion-induced pattern formation on elemental and compound surfaces. The crater function formalism is applied and moments of the crater function were calculated using Monte Carlo simulations with the program SDTrimSP. The extensions to the linear theories give rise to additional curvature coefficients which have relevant impact on the formation of parallel ripples. The thickness dependence leads to a stabilizing contribution at intermediate angles. The curvature dependence of the crater function leads to a stabilizing contribution, except for larger angles where it becomes strongly destabilizing. With these extensions, the combination of BH and CV theory is able to quantitatively predict the angular regime for parallel ripple formation, the ripple wavelength and the initial growth rates. In particular, the extended theories are able to explain the absence of pattern formation in certain cases.

[1] M.P. Harrison,R.M. Bradley, Phys.Rev.B 89,245401(2014).

[2] H. Hofsäss, Appl. Phys. A 114 401 (2014).