Nanosized induced low-temperature alloying in binary and ternary noble alloy systems for micro-interconnect applications

This study introduces and demonstrates the concept of low-temperature alloying due to the nanosize effect. The interactions between noble metallic nanoparticle deposits (NPD), including Au and bimetallic Ag3Au, and bulk substrates (Ag, Cu and Ni) upon heating were investigated systematically. According to the experimental results, in the very early stage of heating at temperatures higher than the melting points of nanoparticles, which are substantially lower than those in the bulk state, the supercooled liquid reacted with the substrate and gave rise to binary or ternary alloying. The reaction products under such non-equilibrium conditions reveal a variety of metallurgical features depending on the nature of the NPD/substrate systems.