INCORPORATION KINETICS OF AS-2 AND AS-4 ON GAAS(110)

Reflection high energy electron diffraction (RHEED) intensity oscillat ions have been used to obtain the arsenic incorporation coefficient fo r the growth of GaAs on GaAs(110) by molecular beam epitaxy (MBE) usin g either As-2 or As-4 as the source of arsenic. In both cases, the inc orporation coefficients decrease with increasing growth temperature, w ith the values obtained for As-2 being approximately twice those of As -4. The results are modelled within a kinetic scheme based on the assu mption that the incorporation processes are precursor mediated and in both cases involve a molecularly adsorbed As-2 intermediate. The diffe rence in the activation energies for the desorption and incorporation of the As-2 intermediate is the same when using either As-2 or As-4. T he implication is that the final incorporation step in the growth of G aAs(110) is independent of the arsenic species used.