Metalorganic chemical vapor deposition of TiN films for advanced metallization

Titanium nitride (TiN) films are used extensively in advanced metallization schemes for ultralarge scale integrated applications. In the present experiments, physical properties of thin TiN films deposited using low pressure chemical vapor deposition from tetrakis-dimethyl-amino titanium and ammonia have been investigated. Deposited films were characterized by resistivity, stoichiometry and etch rates. It was found that bulk resistivity correlated to wet etch rates with high resistivity films having higher wet etch rates. High bulk resistivity films were unstable in atmosphere and Auger analysis showed higher relative oxygen content. It is concluded that high resistivity films are low density and thereby susceptible to ex situ contamination. Optimized films had bulk resistivity of 250 μΩ cm and wet etch rates comparable to reactively sputtered TiN.