Hydrazine adsorption and decomposition on the GaAs(100)-c(8 x 2) surface

Abstract

Temperature programmed desorption (TPD), X-ray photoelectron spectroscopy (XPS), and high resolution electron energy loss spectroscopy (HREELS) have been used to study the decomposition mechanism of hydrazine (N2H4) on the GaAs(100)-c(8 x 2) surface. Hydrazine adsorbs in a "side on" manner as indicated by XPS results. For small doses, hydrazine decomposition is complete, and the major decomposition product is ammonia, with nitrogen and hydrogen also being formed. For large doses, nitrogen is the major gas phase decomposition product. The absence of a high temperature atomic nitrogen recombination TPD peak indicates that nitrogen is made through an intramolecular mechanism. Both N2Hy and NHx species (y = 1, 2, 3; x = 1, 2) are identified as reaction intermediates. Above 350 K, only NHx species are present on the surface.