Characterization of Carbon Contained Films at Bonding Interface for the Application of Backside Power Delivery Networks

Direct Bonding is gaining attention increasingly as a critical process in the advanced 3D architecture like BSPDN. Achieving new structures in advanced nodes requires robust bonding that ensures high bonding strength, low distortion, and high reliability. However, remaining water at the bonding interface, which affects reliability, is difficult to consume at low temperatures with conventional <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{SiO}_{2}$</tex> dielectricfilms. Wafer to wafer bonding was performed and the bonding interface was evaluated by using a newly developed Carbon Contained Film (CCF). A film with highly efficient interfacial <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{H}_{2}\mathrm{O}$</tex> consumption ability was identified. To distinguish the differences of the ability between the films, their water content and surface functional active sites were characterized. Additionally, investigation of the bonding interface mechanism revealed a unique C-rich layer, which consumes more interfacial water at low temperatures.