Growth oscillations with monolayer periodicity monitored by ellipsometry during metalorganic vapor phase epitaxy of GaAs(001)

In this letter we report on the observation of growth oscillations with monolayer periodicity by ellipsometry. An oscillation amplitude of δ〈e1〉=0.05 was measured using an optimized spectroscopic in situ ellipsometer whose wavelength was tuned to the 2.65 eV resonance energy of the arsenic dimers covering the GaAs (001) growth surface. The monolayer periodicity was verified by parallel monitoring of the growth with reflectance anisotropy spectroscopy (RAS).