Some properties of r.f.-sputtered hafnium nitride coatings

Abstract Hafnium nitride coatings were deposited by reactive r.f. sputtering from a hafnium target in nitrogen and argon gas mixtures. The rate of deposition, the composition, the electrical resistivity and the complex index of refraction were investigated as functions of the target-to-substrate distance and the nitrogen fraction f N2 in the sputtering atmosphere. It was found that the relative composition of the coatings is independent of f N2 for values above 0.1. The electrical resistivity of the hafnium nitride films changes over 8 orders of magnitude when f N2 changes from 0.10 to 0.85. The index of refraction is almost constant at 2.8(1−0.3 i ) up to f N =0.40 then decreases to 2.1(1−0.1 i ) for higher values of f N2 .