Interface and relaxation properties of chemical beam epitaxy grown GaP/GaAs structures

Abstract

In this work, the influence of phosphorus exposure on As-stabilized GaAs(100) surfaces over a temperature range between 500 and 580 °C is studied using a combination of reflection high-energy electron reflection (RHEED) and x-ray diffraction analysis. Through x-ray wave field analysis, it is found that 1 ML of GaP is formed during phosphorus exposure of an As-stabilized (2×4) GaAs surface. Furthermore, relaxation properties of GaP/GaAs(100) (3.8% lattice mismatch), grown by chemical beam epitaxy, are investigated using real-time RHEED oscillation analysis. Although RHEED analysis suggests that the GaP critical thickness, where the onset of relaxation occurs, increases at lower temperatures, x-ray diffraction data indicate a constant critical thickness of 5 ML in the temperature range covered in this study.