Incorporating Niobium in MoS₂ at BEOL-Compatible Temperatures and its Impact on Copper Diffusion Barrier Performance

The continuous scaling of transistors has led to unprecedented challenges for interconnect technologies. Conventional barriers fail when thinned below 4 nm; therefore, novel materials and back-end-of-line (BEOL) compatible synthesis are urgently needed. 2D transition metal dichalcogenides present a unique opportunity for addressing the scaling of interconnects. Here, nanometer thick Nb-incorporated MoS₂ is successfully synthesized at BEOL compatible temperatures and their abilities of blocking Cu atom diffusion are investigated. Nb incorporation of MoS₂ is systematically studied at 450 °C and its growth dynamics is compared with those carried out at high temperatures. The addition of a few percent Nb in MoS₂ enhances breakdown time by more than 100×, reaching a failure time >12 500 s under the electric field of 7 MV cm⁻¹. These results suggest that integration of Nb-incorporated MoS₂ in electronic technologies is a promising route for the sub-5 nm technology node.