NITRALD (Process development and mechanistic investigation of barrier materials for advanced interconnect technology)
Copper wiring (‘interconnect’) is the most urgent roadblock holding up manufacture of electronic devices at 10 nm node and beyond. Interconnect becomes slower as size is reduced, unless the overall resistance can be reduced, which means thinning down the barrier layers that prevent copper from contaminating the chip. Atomic layer deposition (ALD) is the process of choice for 1-2 nm films in deep structures. However barrier metals (Ru, Co) form islands while barrier nitrides (TaN, TiN) cannot be directly copper-plated. This project will systematically investigate a range of transition metals and their nitrides, developing a detailed understanding of ALD mechanism for control of composition and morphology. We will achieve this by combining the unique expertise of Tyndall National Institute (Ireland) in quantum chemical modelling of ALD with that of Fudan University (China) in in-situ monitoring of film growth. We propose RuTaN and CoW(N) as potential single-layer barrier+liner materials. We will develop an NH3-plasma ALD process with control of thickness and stoichiometry, producing films that are smooth, amorphous, continuous at nm-scale thicknesses, conformal in 3D structures and uniform to within 5% over 100 mm wafers. Such a process will break through the bottleneck for interconnect technology in future advanced integrated circuits.
Tyndall, Fudan University
This project has received funding from Science Foundation Ireland (17/NSFC/5279).