Eur. Phys. J. B (2013) 86: 60
https://doi.org/10.1140/epjb/e2012-30884-4

Regular Article

Slope selection of mounds with permeable steps in homoepitaxy

¹ Departement Fisica Fundamental, UNED, c/Senda del Rey 9, 28080 Madrid, Spain
² Institute of Solid State Physics, Bulgarian Academy of Sciences, 1784 Sofia, Bulgaria
³ Escuela Politecnica Superior, Universidad Autónoma de Madrid, 28049 Madrid, Spain
⁴ Institute of Physical Chemistry, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria

^a e-mail: imarkov@ipc.bas.bg

Received: 28 September 2012
Received in final form: 10 December 2012
Published online: 18 February 2013

Abstract

We study the growth of mounds representing stacks of monolayer islands in homoepitaxy assuming terrace-edge-kink mechanism of attachment of atoms to kink sites and allowing a permeability of the single steps. We show that the latter can result in slope selection of the growing mounds at comparatively small values of the Ehrlich-Schwoebel barrier to down-step diffusion. The value of the permeability coefficient at which a slope selection occurs is always very close to the upper limit for complete step permeability. The latter is in agreement with the row-by-row mechanism of step propagation at which the steps are kink-free for most of the time.