CELLULAR STRUCTURES IN STEP-FLOW GROWTH

We investigate numerically the existence of steady cellular patterns d uring step-flow growth. Using an integrodifferential method we determi ne the cellular shapes arising after the straight step has become unst able. We discuss the most general model for a train of steps, in which the step adatoms have finite sticking coefficients, and its restricti ons, such as an isolated step in the one-sided model. We find, dependi ng on the material parameters, a supercritical or subcritical bifurcat ion to a cellular profile. When the sticking coefficients of adatoms f rom both the upper and lower terraces are finite but different (the so -called Schwoebel effect), we find that the depth of the cells increas es significantly. Since the visualization of the cellular depth is by now accessible, the present analysis constitutes an important basis fo r experimental investigation on the role of the adatoms's kinetic atta chment to the step.