Deposition of Ti–B–N films by ICP assisted sputtering

Ti–B–N coatings were prepared by inductively coupled plasma assisted DC magnetron sputtering using a TiB2 target and a gas mixture of N2 and Ar at 200 °C and a pressure of 60 mTorr. In addition to ICP, the effect of the substrate bias voltage on the structure and properties of the coating was investigated. By applying ICP the hardness of the TiB2 coating was increased by more than 60 GPa, as a result of enhanced ionization in the plasma. By adding N2 into the TiB2 coating, the hardness decreased as reported previously. However, the hardness could be increased up to 76 GPa by applying ICP and a bias voltage to the substrate. The Ti–B–N coating, which had the highest hardness, showed the best surface uniformity and a very dense structure with a grain size of 3 nm. This sample also showed a high crystallinity compared to the coating prepared using other deposition parameters.