Decomposition Mechanism of Triethyl-Arsenic on a GaAs Surface for Metalorganic Molecular-Beam Epitaxy: Role of Hydrogen Radicals

Growth of GaAs in metalorganic molecular-beam epitaxy using triethyl-arsenic (TEAs) becomes possible only when TEAs is thermally precracked or when hydrogen (H) plasma is irradiated simultaneously. In this paper, it will be shown that the bottleneck in the growth of GaAs with TEAs is the quick desorption of the As-intermediate species before its decomposition to supply As to a GaAs surface. The Ga-stabilized GaAs surface after the TEAs supply is proposed to be covered with stable C2H4 species based on reflection high-energy electron diffraction and quadrupole mass spectrometric measurements. H radicals are shown to be effective in the initial stages of the decomposition process of TEAs, but once the surface is covered stably with C2H4, even the H radicals cannot enhance their desorption.