Friction-enhanced formation of Cu microwire on Si wafer.

Abstract

Tribological printing is emerging as a promising technique for micro/nano manufacturing. A significant challenge is enhancing efficiency and minimizing the need for thousands of sliding cycles to create nano- or microstructures (2018ACS Appl. Mater. Inter.10 335-47, 2019 Nanotechnology30 302). This study presents a rapid approach for forming Cu microwires on Si wafers through a friction method during the evaporation of an ethanol-based lubricant containing Cu nanoparticles. The preparation time is influenced by the volume of the lubricant added, with optimal conditions reducing the time to 300 s (600 sliding cycles) for producing Cu microwires with a thickness of 200 nm. Key aspects include the lubricating effect of ethanol on the friction pairs and the role of ethanol evaporation in the growth of Cu microwires. Successful formation requires a careful balance between microwire thickening and wear removal. The resulting Cu microwires demonstrate mechanical and electrical properties that make them suitable as micro conductors. This work provides a novel approach for fabricating conductive microstructures on Si surfaces and other curved surfaces, offering potential applications in microelectronics and sensor technologies.