Nanopatterning of Periodically Strained Surfaces - A Kinetic Monte Carlo Simulation Study
M.I. Larsson, R.F. Sabiryanov, K. Cho, B.M. Clemens
Dept. of Materials Sci. and Eng., Stanford University, US
Keywords: nanopattern, selforganization, kinetic Monte Carlo simulation, strain, Ehrlich-Schwoebel barrier
We present kinetic Monte Carlo simulations of nanopatterning by using strain-assisted nucleation of adatom islands on periodically strained fcc(111) surfaces. The goal of our work is to predict conditions and limitations for producing nanopatterns. It is presumed in the model that there is a capping layer of optional thickness terminated by an atomically flat surface above a dislocated interface. By varying the dislocation spacing and geometry, as well as the capping layer material and thickness, the surface strain field can be modified.
Various aspects of strain-assisted nanopatterning of Co and Ag islands on periodically strained Pt(111) and Ag(111) surfaces, respectively, are investigated. The optimal growth conditions for various material systems can be predicted, as we demonstrate for the model system Co on Pt(111).
We study also the effects on the selforganization of strain-relaxed adatom islands and finally the effect of modified potential energy barriers at step edges, i.e. the Ehrlich-Schwoebel (ES) barriers. The ES-barrier simulations mimic the growth of Ag and Co with and without a suitable surfactant. Both strain relaxation and ES barriers are found to be of large importance for the nanopatterning.
NSTI Nanotech 2003 Conference Technical Program Abstract