The reactions of diethylzinc on gallium-rich and arsenic-rich reconstructions of GaAs(100)

Abstract

Temperature programmed desorption (TPD) and high-resolution electron energy loss spectroscopy (HREELS) were used to investigate the reaction of diethylzinc (DEZ) on the Ga-rich (4×2) and As-rich (2×4) and c(4×4) reconstructions of GaAs(100). DEZ dissociatively adsorbed on all three surfaces to form ethyl groups and Zn atoms. The strength of Zn–surface interaction was found to be a function of surface As/Ga ratio. Adsorbed Zn atoms desorbed at 560 K on the Ga-rich (4×2) reconstruction and 585 K on the As-rich (2×4) reconstruction. For the c(4×4) surface, the primary Zn desorption feature was also at 585 K; however, additional Zn desorption features appeared between 600 and 700 K. In contrast to the interaction of Zn with GaAs(100), only minor variations in the reaction pathways for surface ethyl groups were observed as the surface As/Ga ratio was varied. The primary reaction pathway for ethyl groups on all three surfaces was β-hydride elimination at 570 K to produce ethylene. The ethylene yield was found to increase with increasing surface Ga concentration.