Si 2p Core-level Spectroscopy Research Articles

Corrigendum to “Initial oxidation states on Si(001) surface induced by translational kinetic energy of O2 at room temperature studied by Si-2p core-level spectroscopy using synchrotron radiation” [Surf. Sci. 482–485, 189–195 (2001)

Corrigendum to “Initial oxidation states on Si(001) surface induced by translational kinetic energy of O2 at room temperature studied by Si-2p core-level spectroscopy using synchrotron radiation” [Surf. Sci. 482–485, 189–195 (2001)

Erratum to “In-situ Si-2p core-level spectroscopy using synchrotron radiation for initial oxidation on Si(001) surfaces induced by translational kinetic energy of O<sub>2</sub> molecules”

Erratum to “In-situ Si-2p core-level spectroscopy using synchrotron radiation for initial oxidation on Si(001) surfaces induced by translational kinetic energy of O<sub>2</sub> molecules”

Biological functionalization of the amine-terminated Si(100) surface by glycine

A peptide reaction of glycine on an amine-terminated Si(100) surface was investigated using C 1s, N 1s, O 1s, and Si 2p core-level spectroscopy, where the amine-terminated Si(100) surface was prepared using NH 3. In-situ thermal treatments at a mild temperature of 50 °C after the adsorption of glycine on a room-temperature amine-terminated Si(100) surface induced the peptide reaction between the carboxyl group of glycine and the amine group of the surface. This suggests that the amine-terminated Si(100) surface can be an excellent template for constructing a junction between a biomaterial and a Si surface using a dry process.

Chemical phase transitions of a Si oxide film on SiC by MeV electron beam irradiation

An ultrathin Si oxide film grown on a 6H-SiC(0001) wafer was irradiated with 1MeV electron beam to examine its effect on the chemical species of a Si oxide/SiC wafer, where the Si oxide film was composed of SiO2, Si suboxides (Si3+, Si2+, and Si1+), and Si oxycarbides (Si–C–O). Scanning photoelectron microscopy and Si 2p core-level spectroscopy show that e-beam irradiation induces chemical phase transitions from the Si suboxides and Si oxycarbides to SiO2. This suggests that e-beam irradiation is an efficient and simple method of producing a chemically uniform SiO2 film on SiC without thermal and chemical treatments.

Atomic structure of theEu∕Si(111)3×2,5×1, and7×1surfaces studied by photoelectron spectroscopy

Eu-induced Si(111)3x2, 5x1, and 7x1 reconstructions have been investigated by low-energy electron diffraction (LEED) and high-resolution photoelectron spectroscopy using synchrotron radiation. According to LEED, the 3x2, 5x1, and 7x1 phases can be produced on the dominating area of the Si substrate at the 0.20, 0.40, and 0.45 monolayer (ML), respectively, and no contributions from other phases are found in the LEED patterns at these coverages. The Eu 4f spectra show that the 3x2, 5x1, and 7x1 surfaces are semiconducting, and that the Eu atoms are completely divalent in these reconstructions. Si 2p core-level spectroscopy measurements performed at various photon energies and emission angles reveal three surface-related components with core-level shifts of -0.51, -0.20, and +0.17 eV with respect to the bulk component for the 3x2 surface. In addition to these components, two other components with shifts of -0.78 eV and +0.28 eV are found for the 5x1 and 7x1 surfaces. These results are discussed in the context of previous studies and structural models reported in the literature. It is shown that the present photoemission data obtained for the 3x2 surface are well consistent with the honeycomb-chain-channel (HCC) model with an adsorbate coverage of 1/6 ML. For the 5x1 and 7x1more » surfaces, we propose atomic models which include combinations of honeycomb and {pi}-bonded Seiwatz chains, with adsorbate coverages of 2/5 and 3/7 ML, respectively. Based on the LEED and Si 2p core-level results, a local x2 periodicity is expected for the 5x1 and 7x1 reconstructions, which is in good agreement with the nonmetallic electronic structure of these phases.« less

Thermal reactions at the interface between Si and C nanoparticles: nanotube self-assembling and transformation into SiC

The thermal reactions induced in C nanoparticles films deposited on Si substrates were followed by high resolution C 1s and Si 2p core level spectroscopy. These particles, when annealed at ∼1300 K transform into single wall carbon nanotubes [Appl. Phys. Lett. 80 (2002) 1441; Chem. Phys. Lett. 355 (2002) 395]. With increasing temperature a progressive re-hybridization of the sp 3 into the sp 2 carbon phase was observed. At 1270 K the C 1s core level showed a major component at 284.29 eV related to the graphitic tubes, and minor one at 283.75 eV, attributed to CSi bonds at the interface, which however do not seem to participate in the nanotube self-assembling. A strong reaction between Si atoms evaporated from the substrate and nanotube walls was observed at 1400 K, which led to the formation of stoichiometric SiC, occurring as a site-confined reaction.

Initial oxidation states on Si(0 0 1) surface induced by translational kinetic energy of O2 at room temperature studied by Si-2p core-level spectroscopy using synchrotron radiation

Initial oxidation states on Si(001) surfaces caused by the translational kinetic energy (Et) of O2 at room temperature have been studied by the Si-2p core-level spectroscopy using synchrotron radiation. From the results of oxygen coverages as a function of the translational kinetic energy of O2 studied by the O-1s photoemission spectroscopy, it was found that there were potential energy barriers at Et=1.0eV corresponding to the backbond oxidation of the top-layer Si atoms and at Et=2.6eV associated with the oxidation between the second and the third Si layer. The relation between oxidation states (Si1+, Si2+, Si3+ and Si4+) and the translational kinetic energy of O2 were investigated by the high-resolution Si-2p core-level spectroscopy.

Oxidation of the H-Si(111)-1×1 surface: high resolution Si 2p core-level spectroscopy with synchrotron radiation

The room temperature oxidation of H-terminated Si(111) surfaces by activated oxygen has been investigated using high resolution (70 meV) Si 2p core-level spectroscopy with synchrotron radiation. The data are compared with previous studies using photoemission spectroscopy and high resolution electron energy loss spectroscopy. The metastability of the oxidized layer formed at room temperature is also examined.

Si 2p core level spectroscopy in Si(001)2×1: the charge-transfer effect

Analysis of high-resolution Si 2p photoemission spectra recorded from a clean Si(001)2×1 surface clearly reveals seven components. Four of them are surface-related emission with core-level binding-energy shifts (SCLS) of −500, 278, −200, and 138 meV, which are associated with up and down atoms in the dimers, atoms in symmetric dimers, and subsurface atoms, respectively. The other two loss components appear at 1.3 and 1.75 eV, associated with the bulk and surface, respectively. The latter loss structure corresponds to the transitions of dimer-related electronic states. The components assigned to the surface dimer show significant line shifts and broadenings upon C 60 adsorption, whereas the component to the subsurface layer does not. The present result from a modified model function supports the predominance of the initial charge-transfer effect to the SCLS in Si, as in the case of Si(111)7×7.

Surface Infrared Studies of Silicon/Silicon Oxide Interfaces Derived from Hydridosilsesquioxane Clusters

Hydridosilsesquioxane-based model systems have been developed over the past five years to help elucidate the structure and reactivity properties of silicon/silicon oxide interfaces. In this paper, the assignment of infrared bands as Si−O or Si−H derived is explored via deuterium labeling studies. In particular, the issue of the presence of adventitious water in the model interfaces is directly addressed via the chemisorption of deuterated-spherosiloxane clusters (D8Si8O12) onto clean Si(100). The experiments definitively demonstrate that there are no water-derived features detectable by RAIRS in the model interfaces. This rules out water contamination as a possible explanation for the 1.0 eV shifted feature observed in Si 2p core-level spectroscopy for the model systems. This work is further supported by cluster and water co-dosing experiments on Si(100), which address the spectroscopic sensitivity of surface silicon−hydrides in this system. Finally, the first surface crystallographic studies of the model...