Atomic layer epitaxy (ALE) has received considerable attention as a novel approach to crystal growth in nanotechnology. A central idea in ALE is a self-limiting mechanism that automatically stops the layer growth at a certain atomic layers and therefore allows complete control of the layer thickness with single atomic layer accuracy.
In homoepitaxies, ALE proved a great success. However, many difficulties appeared in some heteroepitaxies where the self-limiting was easily broken. Even the growthof a simple heterosturucture of eaptaxial layer A on epitaxial layer B requres three types of ALEs; ALE for epitaxial layer B on epitaxial layer B (homoepitaxy), ALE for epitaxial layer A on epitaxial layer B (heteroeptaxy), and ALE for epitaxial layer A on epitaxial layer A (homoepitaxy).
We have investigated the self-limiting mechanism in the ALEs of InAs/GaAs and GaP/GaAs heteroeptxies and strained layered superlattices. Superlattices were grown on GaAs(001) and InP(001) by "Pulsed-Jet-Epitaxy" with trimethylgallium, trimethylindium, trisdimethylaminoarsine, and phosphine as source materials. We report that the strain between epitaxial layer and the substrate, an atomic level surface morphology, and an interface electric neutrality had great effects on the self-limiting mechanism in heteroepitaxy.