The scaling limit of conventional Cu diffusion barriers has become the bottleneck for interconnect technology, which in turn limits the IC performance. Sub-nm diffusion barrier is urgently demanded to maintain the interconnect resistivity for ultra-scaled Cu interconnects. However, with this thickness, the blocking capabilities of conventional Cu diffusion barriers are lost. In this letter, sub-nm Cu diffusion barrier is realized by single-layer molybdenum disulfide (MoS2) grown at 400 °C using metal-organic chemical vapor deposition. MoS2 is directly grown on dielectrics without transfer processes and the continuous coverage in a large area (>1 cm2) is achieved. Its resistance to Cu diffusion is investigated by time-dependent dielectric breakdown (TDDB) measurements. Our results indicate that the MoS2 barrier can efficiently suppress Cu diffusion and enhance dielectric lifetime significantly. Although a few challenges, including Cu adhesion to the MoS2 surface and integration with the Damascene structure, have to be assessed before introducing this novel material to the back-end-of-line technology, our work lays the groundwork for further investigation.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering