Phosphorus and arsenic incorporation during chemical beam epitaxial growth of strained GaAs1-xPx layers on GaAs(100) substrates

Phosphorus and arsenic incorporation during chemical beam epitaxial growth (CBE) of GaAs_1-xP_x using triethylgallium (TEGa), tertiarybutylarsine (TBAs) and tertiarybutylphosphine (TBP) as precursors has been studied. Reflection high-energy electron diffraction intensity oscillations are used to measure the arsenic and phosphorus incorporation during group V controlled growth on a Ga-rich surface for different TBAs and TBAs+TBP fluxes. The so obtained phosphorus mole fraction is compared with the phosphorus composition measured by x-ray rocking curves on the strained GaAs_1-xP_x layers grown by conventional CBE with simultaneous supply of the group III and group V precursors and by atomic layer epitaxy (ALE) alternating the group III and group V fluxes. The phosphorus incorporation rate during CBE growth is lower than that measured during ALE and group V controlled growth but is still much higher than the incorporation rate reported for molecular beam epitaxial growth using elemental sources. Photoluminescence spectra show clearly strain effects in the heavy and light hole excitonic transitions