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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.

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Ethylated silanes and germanes are promising candidates for heterojunction atomic layer epitaxy of SiGe devices. However, thermal dissociation of unwanted ligands in the parent molecules usually is not suitable for device fabrication. Hence, alternative means for dissociation employing low thermal budgets are desirable. In this work, an electron beam was used to irradiate diethylsilane (DES)-covered Si(100) surfaces at 100 K in order to initiate non-thermal, electron-driven dissociation and desorption processes in the adsorbed species. Clean Si(100) surfaces were dosed with gas-phase DES molecules at 100 K followed by irradiation with 600-eV electrons (current density 5.4 µAcm −2 ). The effects of electron irradiation were investigated by obtaining x-ray photoelectron spectra before and after exposing the DES/Si(100) to the electron beam. Shifts in the binding energy of the C 1s photoelectron peak and a decrease in the total surface carbon concentration are indicative of dehydrogenation and removal of carbon species by electron irradiation. Our results suggest the possibility of electron-beam-assisted b-hydride elimination at 100 K as one channel for surface carbon removal.