Quantitative assessment of adhesion strength in hybrid bonded interfaces with varying metal contact density

Abstract

This work systematically investigates the influence of metal contact density and pitch size on the adhesion strength of hybrid bonded interfaces using an energy-based nanoindentation methodology to quantify interfacial bond strength. Results show that the presence of metal at the bonding interface enhances adhesion strength of hybrid bonded interfaces, with the effect becoming increasingly pronounced for lower pitch sizes. This enhancement is attributed to the role of metal/metal interfaces as crack-arresting sites during interfacial fracture. The findings in this work provide critical insights for optimizing hybrid bonding designs in advanced interconnect technologies.