Relationship between composition, bonding constitution and microstructure in unbalanced magnetron sputtered Ti-B-N thin films

Two types of Ti-B-N thin films with different B contents were deposited on Si(100) at room temperature at different nitrogen flowrates. Their phase configurations and microstructures were subsequently characterised. The results indicated that the nitrogen flowrate greatly affected phase configuration and film composition. At a low nitrogen flowrate, TiN bonding was preferentially formed, accompanying with small amounts of TiB and TiB₂ bonds. Formation of TiB₂ bonding was accelerated with increasing B content. Nanocomposite thin films mainly consisting of nanocrystalline (nc-) TiN/amorphous (a-) TiB₂ were finally formed. At a high nitrogen flowrate, TiN followed by BN was first formed, accompanying with small amounts of TiB and TiB₂ bonds. Formation of BN bonding was further accelerated with increasing B content. Nanocomposite thin films mainly consisting of nc-TiN and a-BN were finally produced. The present thin films are the nanocomposite of nc-TiN embedded in the a-matrix with a dense microstructure despite of the nitrogen flowrate. © 2007 Institute of Materials, Minerals and Mining.