Kinetics of Convergence the Si(100) Surface Steps

Abstract

The convergence kinetics of S_A and S_B steps on Si(100) substrates with inclination of 0.5° and 0.1° are studied. To establish the character of the growth kinetics, the time dependences of the reflection high‑energy electron diffraction (RHEED) intensity are analyzed. It is shown that the convergence rate of the steps in the Si at a growth rate of 0.37 ML/s has a decreasing dependence with an increase temperature. It is found that the rate of formation of a single-domain surface increases with the width of terraces on the surface, which is likely to be related to a partial participation of the growth due to the formation of two-dimensional islands. At temperatures higher 650°С, the dominant growth mode due to the motion of the steps and the rate of formation of the single-domain surface decrease with an increase in the terrace width. Thus, the convergence of single-layer steps is determined by the conditions of the growth of the molecular-beam epitaxy (MBE) and also by the Si(100) substrate orientation. The convergence of S_A and S_B steps of the Si(100) surface is explained by a slow-down motion of S_A which is related to complex mechanisms of permeability and the formation of step kinks. It is assumed that the cause of the slow-down convergence the steps with increasing temperature is an increase in the kink density on the S_A step, which decreases the permeability coefficient of the S_A step.