Resistivity Scaling of Rhodium Nanowires for Advanced Interconnect Applications

This study investigates the material and electrical properties of thin Rh films and nanowires. As-deposited Rh thin films with thicknesses below 30 nm are polycrystalline and show rapid grain growth at approximately 350 °C, forming a microstructure dominated by a (111) fiber texture. Compared to Cu, Rh thin films demonstrate a weaker film thickness dependence of the resistivity, leading to a resistivity crossover around 10 nm. The resistivity scaling of these films can be described by the semiclassical Mayadas–Shatzkes model, with grain boundary scattering the limiting factor. Furthermore, Rh nanowires with cross-sectional areas below 70 nm 2, fabricated using a metal-spacer etching process, exhibit superior resistivity scaling compared to Ru and Co nanowires, with the potential to significantly outperform state-of-the-art Cu interconnects at line widths around 10 nm. These findings highlight Rh as a promising candidate metal for advanced microelectronic interconnects.