Bond Wave Analysis of SiCN for Fine Pitch Hybrid Bonding

Hybrid bonding has emerged as a key technology in advanced three-dimensional (3D) integration, yet challenges for further bonding alignment accuracy remain towards below 200 nm pitch. The scaling error of the bonding alignment can be controlled by understanding of the bonding dynamics such as the bond wave. This study investigates the bonding dynamics with PECVD-SiCN as a superior dielectric material. The pre-bonding surface were characterized by VSFG spectroscopy and zeta potential analysis. Direct bonding experiments using 300 mm SiCN wafers demonstrate that bond wave propagation is governed by three critical factors: surface functional groups and carbon content. Interestingly, no correlation was found between bond wave speed and bond strength. These insights provide a deeper understanding of bonding mechanisms, facilitating process refinements for improved hybrid bonding quality.