XPS study of electron‐induced surface processes in trimethylsilane‐covered Ge(100) surfaces

Abstract

X-ray photoelectron spectroscopy (XPS) was used to study the effects of electron beam irradiation of a multilayer film of trimethylsilane on a clean Ge(100) surface at −150• C. Core level C 1s, Si 2p, and Ge 3d photoelectrons were monitored at the same experimental conditions after various electron fluences. Electron irradiation is observed to cause an increase in the relative silicon surface concentration with a corresponding decrease in the carbon concentration. No change was evident in the surface germanium concentration, although electron irradiation resulted in an increasing concentration of C-Ge bonds with time. Simultaneously, the concentration of C-Si bonds decreased as a function of irradiation time. Growth of silicon islands is postulated as a possible explanation for this observation. The possible silicon island growth proposal is supported by the observed gradual decrease in concentration of Si-Si bonds, which would occur as the fraction of the surface covered by silicon decreases.

Adsorption Configuration Change of Pyridine on Ge(100): Dependence on Exposure Amount

“…This means that there are chemically four different environments of C atoms in the pyridine adsorbed on the Ge−Ge dimer. Since the C 1s peak positions for strongly bound molecule on Si or Ge surfaces are reported to be 284.20 ± 0.50 eV, − features A and B do not correspond to the C atoms in the pyridine bound strongly to the Ge−Ge dimers. Instead, these binding energy positions confirm that the initial adsorption of pyridine on Ge(100) is characterized primarily by the Ge−N dative bonding configuration with all other C atoms intact as shown in Figure b.…”