Improved Diffusion-Resistant Ability of Multicomponent Nitrides: From Unitary TiN to Senary High-Entropy (TiTaCrZrAlRu)N

Multicomponent high-entropy nitrides have been attempted as robust diffusion barrier materials to inhibit the severe interdiffusion of Cu and Si; however, the improvement in their diffusion resistance relative to the abilities of few-component nitrides has actually not been verified. Thus, in this study, nitride barriers with different numbers of components (metallic elements), from unitary TiN to senary high-entropy (TiTaCrZrAlRu)N (with the same face-centered cubic structure and a thickness of 5 nm), were prepared. The failure of these nitride barriers in resisting the interdiffusion of Cu and Si was examined, and the activation energy of Cu diffusion through the nitrides was determined. With more components incorporated, the failure temperature of the nitrides was found to markedly increase from 550A degrees C to 900A degrees C, and the activation energy of Cu diffusion was effectively raised from 107 kJ/mol to 161 kJ/mol. Severe lattice distortions and random cohesions are suggested as the dominant factors for the improved diffusion-resistant ability of the multicomponent high-entropy nitrides.