Tadatomo Suga教授学术报告

报告题目：Surface Activated Bonding for 3D and Heterogeneous Integration——Current Status and Future Prospects

主 讲 人：Tadatomo Suga（须贺唯知） 日本东京大学、明星大学教授

时    间：2025年5月29日(周四)上午9:00-11:00

地    点：安徽大学磬苑校区 行政楼B204会议室

主办单位：集成电路先进材料与技术产教研融合研究院

欢迎各位老师、同学届时前往！

【报告摘要】

This presentation will review the historical development of surface-activated bonding (SAB), summarize its status, and discuss prospects. The SAB method is predicated on the principle of surface activation, achieved through energetic particle bombardment, such as argon fast-atom beam irradiation in an ultra-high vacuum environment. This process effectively cleans and activates surfaces, enabling them to bond with high strength at room temperature without necessitating heat treatment. The standard SAB technique has recently been adapted to include heterogeneous semiconductor wafer bonding and three-dimensional integration. The modified SAB process incorporates surface activation alongside simultaneous co-sputtering of a nano-adhesion layer composed of silicon, metal, or even oxide, facilitating the bonding of materials such as silicon dioxide, ionic crystals, glasses, and polymers.

The application of the SAB method for mass production commenced with the packaging of silicon MEMS sensors. This requirement arose from the need to seal vacuum cavities through direct bonding of silicon wafers, which must be conducted at room temperature to preserve the sensors' characteristics. Currently, the primary application of SAB in mass production involves the bonding of wafers for surface acoustic wave (SAW) filters. This process necessitates directly bonding piezoelectric single-crystal wafers with silicon and sapphire. Due to the significant differences in thermal expansion coefficients, high-temperature bonding is not feasible, as the brittle piezoelectric crystals cannot endure elevated bonding temperatures, requiring room-temperature bonding.Furthermore, SAB is beginning to find applications in the fabrication of photonic devices. Diamond materials are expected to be effective heat spreaders for high-power and RF devices; however, conventional methods are inadequate for directly bonding diamond to wide-bandgap (WBG) semiconductors. SAB has demonstrated effectiveness in bonding these material combinations.

The application of hybrid bonding in the three-dimensional integration of semiconductor devices is progressing. Traditional hybrid bonding technologies typically require heating or post-annealing at temperatures of at least 350°C, which restricts the selection of usable materials and significantly limits the integration of heterogeneous semiconductors. In the current landscape, bonding at 350°C is impractical, necessitating processes at or below 200°C; SABs are also expected to be the trump card for 3D integration of such heterogeneous devices.

【主讲人简介】

Prof. Tadatomo Suga joined the Max-Planck Institut für Metallforschung in 1979 and obtained his Ph.D. in materials science from the University of Stuttgart in 1983. He became a faculty member of the University of Tokyo in 1984 and served as Professor in the Department of Precision Engineering, School of Engineering, from 1993 until his retirement in March 2019. He was appointed Professor Emeritus and subsequently joined Meisei University, where he continues his research activities.

His research focuses on microelectronics and microsystems packaging, particularly on developing critical technologies related to low-temperature bonding and interconnects, with special emphasis on Surface Activated Bonding (SAB). He has also actively promoted collaboration between industry and academia in semiconductor advanced packaging.

In addition to his academic roles, Prof. Suga served as Director of the Research Group of Interconnect Eco-design at the National Institute for Materials Science (NIMS), a Member of the Japan Council of Science, Chair of the IEEE CPMT Society Japan Chapter, and President of the Japan Institute for Electronic Packaging (JIEP). He also chaired the JSPS University-Industry Cooperative Research Committee for Innovative Interface Bonding Technology.