Preparation and characterization of TiN films by electron cyclotron resonance (ECR) sputtering for diffusion barrier applications

An electron cyclotron resonance (ECR) plasma system has been used to deposit TiN films by reactive sputtering process. The effect of magnetic mirror field on the current–voltage characteristics of the cylindrical sputtering cathode has been studied. Stoichiometric TiN films with minimum stress and specific resistivity of 82 μΩ cm and surface roughness of 3 Å have been deposited at a substrate temperature of 350°C. The films showed strong (2 0 0) orientation on Si(1 0 0), Si(1 1 1) and glass substrates. The use of TiN as a barrier layer in copper metalisation has been investigated. No detectable diffusion was observed up to a temperature of 700°C for a film thickness of 600 Å. The resistivity data is in conformity with the RBS depth profiling. The quality of the films has been explained in terms of improved microstructure and packing density as a result of high-density ion bombardment.