RECOVERY KINETICS DURING INTERRUPTED EPITAXIAL-GROWTH

The recovery kinetics upon cessation of growth by molecular-beam epitaxy (MBE) are investigated with Monte Carlo simulations of a solid-on-solid model. The simulations are monitored by calculating both the step density and the kinematic approximation to the reflection high-energy electron-diffraction (RHEED) specular intensity. A comprehensive analysis of recovery includes (1) the microscopic origins of the recovery profile of the specular intensity in RHEED, (2) the isolation of particular recovery processes and the problems associated with interpreting recovery data in terms of elementary events, (3) the dependence of recovery characteristics upon the point in layer completion at which growth is interrupted, (4) the determination of kinetic parameters from recovery data in an experimentally-realizable manner, and so obtaining a parametrization of simple models of MBE, and (5) the influence of diffraction conditions upon the qualitative and quantitative interpretation of RHEED recovery data. Our study illustrates the considerable potential in analyzing recovery data and highlights the fact that recovery is a more discriminating test of models of MBE and of RHEED than simply growth. This derives from the ability to make quantitative comparisons between measured and calculated characteristic times without necessarily resorting to dynamical diffraction calculations. © 1990.