Titanium Nitride Grown by Sputtering for Contacts on Boron-Doped Diamond

Due to its exceptional properties, semiconducting diamond is expected to be used for electrically active devices which can be operated in harsh environments. Such devices need reliable ohmic contacts that can also stand hostile environments. Titanium nitride (TiN) is a chemically stable material with good electrical conductivity. In this work, TiN contacts on boron-doped diamond have been made and characterised. TiN films were deposited by reactive magnetron sputtering. Boron-doped diamond layers were deposited by plasma enhanced chemical vapour deposition. Optimal deposition conditions have been determined to obtain TiN films with low resistivity (∼100 µΩ · cm), high reflectance in the IR region and low stress. TiN contacts show ohmic behaviour after annealing at 750 °C.