Electron-induced surface chemistry on TiN in ultrahigh vacuum

The property of a TiN/vacuum interface in ultrahigh vacuum (<3×10−9 Torr) and under electron beam irradiation was studied using Auger electron spectroscopy. Electron-beam energies ranged from 1 to 9 keV. Without electron irradiation, about 1 monolayer (ML) of oxygen adsorbs on the TiN surface and metal oxidation occurs. The characteristic of oxygen adsorption is discussed in terms of the relationship of gas-sticking probability with coverage within the first ML regime. Under electron irradiation, carbon accumulates on the surface, in addition to oxygen adsorption, which modifies the surface chemistry to an extent that depends on the vacuum conditions, electron current density, and electron beam energy. For high-energy electron beams, electron bombardment induces TiC formation.