Increased epitaxial thickness limit in low-temperature GaAs grown on a vicinal substrate

Abstract

We show that the use of vicinal GaAs(0 0 1) substrates with high misorientation angle inhibits the nucleation of pyramidal defects and hence delays the breakdown of the perfect epitaxial growth of LT-GaAs layers grown under identical growth conditions. The experimental results indicate that surface roughness plays the key role in the breakdown of perfect epitaxy, since our investigations are performed on samples with the same amount of strain. Hence, from the obtained data and taking into account the previously reported results of kinetic growth simulations we conclude that the breakdown of perfect epitaxial growth in LT-GaAs is driven by kinetics.