Oxidation kinetics of TiN thin films

Abstract

We have investigated the oxidation kinetics of TiN thin films in dry O2 in view of a possible application of TiN as material for gate electrodes and interconnections in large-scale integrated circuits. We found that in the temperature range of 500 to 650 °C the oxidation is thermally activated with an activation energy of 2.05±0.05 eV. Thereby the diffusion of oxygen through the oxide is the rate-limiting process. Analysis with x rays indicates that dry oxidation transforms TiN to the rutile form of TiO2. Films of TiO2 formed in such a manner are found to be semi-insulating with resistivities in the order of 106 Ω cm and at higher applied electric fields the injection of space-charge–limited currents is observed.