Rate equation models of epitaxial growth on stepped surfaces

Abstract

We review the rate equation method of modeling epitaxial growth on a flat surface, where the predominant growth mode is via nucleation and growth of adatom islands. We apply a similar method to investigate the step-edge propagation growth mode on stepped (vicinal) surfaces. Unlike the intuitive picture of step-edge propagation whereby the surface morphology is invariant in a moving reference frame, results show oscillations in the step-edge positions about mean values (dependent on initial step-edge distribution). This could have important consequences in the growth of vertical superlattices. We have combined the two previous models to describe a more general case of growth, on stepped surfaces, where both nucleation through adatom islands and step-edge growth occur. Calculated reflection high-energy electron diffraction oscillations from this model will be compared with experimental results.

Remark to the Intensity Measurement of RHEED

“…This oscillation is characterized by the period, amplitude, phase, and damping of the oscillations; the behavior at the initiation of growth; the recovery after growth; and the frequency distribution in the Fourier spectrum of the oscillations. The origin and development of oscillation have been investigated by several authors [2][3][4][5][6][7][8][9]. Many properties and behaviors of the oscillations are not yet understood.…”

Growth Information Carried by Reflection High-Energy Electron Diffraction

“…RHEED oscillations are characterized by their period, amplitude, phase and damping, the behaviour at the initiation of growth, the recovery after growth and the frequency distribution in the Fourier spectrum of the oscillations. The origin and description of RHEED oscillations have been investigated by several authors [2][3][4][5][6][7][8][9]. Many properties and behaviours of the oscillations are not yet understood.…”