Atomic-layer epitaxy of II–VI compound semiconductors

Abstract

Atomic-layer epitaxy (ALE) is a new crystal-growth method, which allows to grow epitaxial layers of compound semiconductors. In contrast to other growth methods in ALE there exists a set of growth parameters, the so-called self-regulatory regime, where layer-by-layer growth occurs. We could prove that in this regime the growth rate is independent of the substrate temperature, and the beam flux intensity. At higher substrate temperatures, we found a second range with a temperature-independent growth rate, where, the average coverage per reaction cycle in less than a full monolayer. A model is presented, which describes this behavior and leads to the prediction that the stability range of the ALE process can be considerably influenced by changing the molecular beam fluxes. This means that timing and dosing of the beam fluxes are the key for the successful design of an ALE process, when smooth layers, and sharp interfaces in an atomic scale have to be grown.