Magnetoresistive, Mechanically Hard Superlattices of CrN, NbN, TiN Multilayers Deposited on Monocrystalline Si Wafers

Hardness measurements on thin films have to face the problem of the effect of the substrate hardness on the obtained result. Also the method of hardness measurement exerts a considerable influence on the experimental data. Some models, which take such effects into account, are presented. We describe experimental results of hardness measurements made with the Vickers 5g probe. Nitride layers (CrN, TiN, NbN), superlattices composed of these nitrides and thin metal films deposited either on the monocrystalline Si or metallic substrates such as steel or copper have been investigated. We also present measurements of the magnetoresistivity (MR) effect. on superlattices, which consist of the multilayers TiN/NbN deposited on Si substrates. Layers of different thickness of TiN and NbN obtained by the reactive sputtering method with different superlattice period values (L) and number have been studied. The composite hardness of the structures (superlattice on Si) was found to reach 80 GPa and MR value in the best probes was ~80% (for fields from some Gs to kGs). When the supporting thin metallic layer was present, then its influence on the composite hardness was also observed.