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

Abstract

The effect of ammonia exposure and substrate temperature on the reaction of ammonia with GaAs(100)-c(8 x 2) has been studied using temperature programmed desorption (TPD), X-ray photoelectron spectroscopy (XPS), and high resolution electron energy loss spectroscopy (HREELS). TPD data indicate that thermal decomposition of ammonia occurs at moderate temperatures (250 K). Above 250 K, recombinative desorption of ammonia is the dominant reaction mechanism. The appearance of the NH2 deformation mode at low exposure and temperature indicates thermal decomposition of ammonia on the GaAs(100)-c(8 x 2) surface.