Growth morphology of epitaxial ErAs/GaAs by x-ray extended range specular reflectivity

Abstract

The growth morphology of ErAs on [001] GaAs with thicknesses ranging from 2 atomic layers to 400 Å is investigated using x-ray specular reflectivity. This epitaxial system displays rich morphological behavior and we observe the evolution from discontinuous to continuous layers at just a few monolayers and qualitative changes occur in layer thickness fluctuations for thicker films having high dislocation densities. We also demonstrate that the reflectivity of a heteroepitaxial system can be measured and modeled over an extended angular range, starting from grazing angles and continuing through the regions of Bragg scattering at higher angles. Disorder in epitaxial layers typically gives a mosaic line broadening transverse to the reflectivity and we show that transverse line shape considerations are crucial to these measurements.

ErAs interlayers for limiting interfacial reactions in Fe/GaAs(100) heterostructures

“…21 Continuous films of ErAs, as thin as ϳ10 Å, can be grown on GaAs with atomically abrupt interfaces. 22,23 The thermodynamic stability and high melting point of ErAs, in combination with its epitaxial compatibility with GaAs, make it a viable diffusion barrier for limiting the Fe-Ga-As reactions at the Fe/GaAs interface. This article will examine the interfacial reactions as a function of temperature and surface reconstruction.…”