Adsorption and decomposition of silane on cu(111)

Abstract

The adsorption and decomposition behavior of silane (SiH4) on Cu(111) surface has been investigated by use of Si K- edge XAFS. Saturated adsorption of silane on Cu(111) at 100K produces the monolayer species, which yields a clear but fragile (√3x√3)R30° LEED pattern. The adsorbed species still has a molecular character and its SiH-XANES spectra show a significant polarization dependence. From the results of XANES and SEXAFS, it is deduced that SiFb fragments adsorb on atop of Cu atoms with the Si-Cu distance of 2.48±0.02A. Heating up to 300K, SiH-XAFS spectra change drastically, indicating that the adsorbed species decomposes to atomic Si to form silicide-like structure. © 1993 The Japan Society of Applied Physics.