Determination of the Ehrlich-Schwoebel barrier in epitaxial growth of thin films

We demonstrate an approach for determining the "effective" Ehrlich-Schwoebel (ES) step-edge barrier, an important kinetic constant to control the interlayer mass transport in epitaxial growth of thin films. The approach exploits the rate difference between the growth and/or decay of an adatom and a vacancy two-dimensional island, which allows the "effective" ES barrier to be determined uniquely by fitting with a single parameter. Application to growth of Pb islands produces an effective ES barrier of ~83±10 meV on Pb(111) surface at room temperature.