CELLULAR STRUCTURES IN STEP-FLOW GROWTH

We investigate numerically the existence of steady cellular patterns during step-flow growth. Using an integrodifferential method we determine the cellular shapes arising after the straight step has become unstable. We discuss the most general model for a train of steps, in which the step adatoms have finite sticking coefficients, and its restrictions, such as an isolated step in the one-sided model. We find, depending on the material parameters, a supercritical or subcritical bifurcation to a cellular profile. When the sticking coefficients of adatoms from both the upper and lower terraces are finite but different (the so-called Schwoebel effect), we find that the depth of the cells increases significantly. Since the visualization of the cellular depth is by now accessible, the present analysis constitutes an important basis for experimental investigation on the role of the adatoms's kinetic attachment to the step.