AVS 59th Annual International Symposium and Exhibition
    Surface Science Thursday Sessions
       Session SS+NS-ThA

Paper SS+NS-ThA4
Influence of Surface Steps on the Initial Oxidation of TiN (100)

Thursday, November 1, 2012, 3:00 pm, Room 21

Session: Surface Science of Nanostructures
Presenter: M. Hong, University of Florida
Authors: M. Hong, University of Florida
S.R. Phillpot, University of Florida
S.B. Sinnott, University of Florida
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Titanium nitride (TiN) film has extreme hardness, high chemical reactivity and high electrical conductivity and thus is widely used for wear and corrosion resistant coatings as well as diffusion barriers and gate electrodes in microelectronic devices. They are thus routinely subjected to extreme conditions such as high pressure and temperature, corrosive environments, and consequently undergo oxidation. Here, density functional theory calculations are used to determine the mechanisms associated with step-related oxidation process and the formation of TiOx induced by both the dissociation of O2 and Ti surface diffusion on TiN (100). Preliminary calculations reveal stable adsorption sites near surface steps for O2 molecules and single O adatoms, both of which have adsorption energies larger than on terraces. This indicates that the dissipated energy during O2 dissociation near the surface step is larger than that on (100) terraces so that consequent oxidation reactions can occur more easily. The calculations reveal potential O2 dissociation paths with activation energies in the range of 1-2 eV. This work is supported by the National Science Foundation (DMR-1005779).