INSITU DETERMINATION OF PHOSPHORUS COMPOSITION IN GAAS1-XPX GROWN BY GAS-SOURCE MOLECULAR-BEAM EPITAXY

We report for the first time an in situ determination of phosphorus compositions in a mixed group-V compound, such as GaAs(1-x)P(x), grown by gas-source molecular beam epitaxy. Reflection high-energy electron diffraction intensity oscillations from As-limited and (As + P)-limited growth are observed on a Ga-rich GaAs surface. The phosphorus composition is therefore deduced from the different growth rates. Viability of this technique is strongly confirmed by the good agreement with the phosphorus compositions determined ex situ by x-ray rocking curve measurements on GaAs/GaAsP strained-layer superlattice structures.