화학공학소재연구정보센터
Thin Solid Films, Vol.370, No.1-2, 45-49, 2000
The microstructure and mechanical properties of TaN/TiN and TaWN/TiN superlattice films
The microstructure and the microhardness of the TaN/TiN and TaWN/TiN superlattice films have been studied with X-ray diffraction, transmission electron microscopy and microhardness tester. The results showed that both TaN/TiN and TaWN/TiN superlattice films have a cubic crystal structure with an epitaxially grown mode of polycrystallinity. Lattice constants of superlattice films are between those of the constituent materials. The superhardness effect was found in TaN/TiN and TaWN/TiN superlattice films and the maximum hardness value was 40.0 GPa at a modulation period of 9.0 nm for TaN/TiN, and 50.0 GPa at a modulation period of 5.6 nm for TaWN/TiN. It is proposed that the lattice mismatch affects the microhardness value and the peak position of maximum hardness. The inhibition of dislocation motion by alternating stress fields of interfacial coherent strains is believed responsible for hardness anomalies.