Molecular mechanics study on mechanical load transfer of dielectric layer to copper pad

Abstract

To enable high-density 3D integration in advanced semiconductors, reliable bonding technologies with thermal resistance and diffusion-blocking properties are essential. While various wafer bonding methods have been proposed, bonding stability along the sidewall interface between dissimilar materials remains insufficiently studied. This research uses all-atom molecular dynamics simulations to characterize mechanical load transfer at the Cu conductor-SiCN dielectric interface. Specifically, the impact of surface composition changes caused by pre-annealing of SiCN on interfacial bonding strength was thoroughly investigated. Results revealed that carbon nanoclusters precipitated onto the SiCN surface at elevated temperatures significantly enhance bonding energy with Cu. Additionally, high-temperature silicon nitride formation alters surface roughness and stress distribution. These findings offer atomic-level insights into optimizing SiCN/Cu interface reliability and mechanical rigidity.