Indium incorporation during the growth of InGaN by molecular-beam epitaxy studied by reflection high-energy electron diffraction intensity oscillations

Abstract

The indium incorporation in hexagonal InGaN grown by plasma assisted molecular-beam epitaxy is studied by means of reflection high-energy electron diffraction (RHEED) intensity oscillations. It is demonstrated that, in addition to being incorporated in the alloy, indium acts as a surfactant, significantly changing the gallium incorporation. This surfactant effect has to be taken into account to allow for a precise in situ determination of the alloy composition. The indium concentrations determined in situ by RHEED intensity oscillations were found to be in good agreement with ex situ results of Rutherford backscattering spectroscopy. This method also allows us to directly assess the maximum In incorporation as a function of the substrate temperature.