Feasibility of the Surface Activated Bonding for Hybrid Bonding and its Alternatives

Presented at the 2026 IEEE Hybrid Bonding Symposium, Jan 21-22, 2026 in Silicon Valley.  More information below.
(23:03) Prof. Tadatomo Suga, Collaborative Research Center, Meisei University
Summary: This presentation reviews the historical development of surface-activated bonding (SAB), summarizes its current status, and discusses future prospects for hybrid bonding and its alternatives. SAB is based on surface activation by energetic particle bombardment, such as argon fast-atom beams under ultra-high vacuum, which removes contaminants and allows strong room-temperature bonding without post-annealing. This technique has been extended to heterogeneous wafer bonding and three-dimensional (3D) integration, offering significant advantages in reducing thermal stress and enabling new material combinations. Hybrid bonding, the leading method for fine-pitch 3D integration, generally requires post-annealing above 350 °C, which restricts material choices and impedes heterogeneous integration. As next-generation devices demand bonding temperatures of 200 °C or lower, SAB is emerging as a promising solution. In addition, alternative low-temperature approaches—such as plasma-assisted bonding, atomic-layer-based surface modification, and all-metal interconnect schemes—are evaluated and compared with SAB in terms of interfacial reliability, manufacturability, and scalability. By highlighting both the potential and limitations of SAB and its alternatives, this presentation provides an outlook on pathways toward reliable, low-temperature hybrid bonding for advanced semiconductor technology.
Bio: Tadatomo Suga joined the Max-Planck Institute für Metallforschung in 1979 and received the Ph.D. degree in materials science from the University of Stuttgart in 1983. Since 1993, he has been a professor at the University of Tokyo. He was also the director of the Research Group of Interconnect Ecodesign at the National Institute of Materials Science (NIMS), and a Member of the Japan Council of Science, as well as the chair of the IEEE CPMT Society Japan Chapter. His research focuses on micro-systems integration and packaging, as well as the development of interconnect technology, especially the room-temperature bonding technique for 3D applications. In March 2019, he retired from the University of Tokyo and joined Meisei University as a professor of the Collaborative Research Center.