Titanium-induced charge of Si(001) surface dependent on local configuration

•The charge transfer near deposited Ti on Si(001) surfaces was estimated by means of high-resolution X-ray photoemission spectroscopy and structurally characterized with scanning tunneling microscopy.•Negative chemical shift of Si due to distorted TiSi bonds was sensitive to the local structure of Ti near a Si dimer.•The shift was reduced when the Ti sank beneath the dimer, and silicidation resulted in a positive shift.•These are consistent with preliminary natural bonding orbital (NBO) calculation applied to inorganic cluster models. High-resolution X-ray photoemission spectroscopy (XPS) was applied to Ti-deposited Si(001) surfaces, which were structurally characterized by means of scanning tunneling microscopy (STM). Negative chemical shift of Si due to Ti deposition was assigned to the distorted TiSi bonds formed on the surface. The shift was reduced when a Ti sank beneath a Si dimer. Silicidation resulted in a positive shift to the TiSi bonding. The charge on the Si atoms near Ti was estimated through preliminary natural bonding orbital (NBO) calculation. We show that the shifts can be explained in terms of the sensitivity of charges of Si near Ti to the local structure near the dimer.