Deep Pitch Scaling of Wafer-to-wafer and Die-to-wafer Cu/SiCN Hybrid Bonding

(25:32 + Q&A) Dr. Anne Jourdain, imec
From the First IEEE Hybrid Bonding Symposium 
Summary: Hybrid bonding is recognized as the key technology for advanced heterogeneous wafer-level system integration. This is enabled through aggressive pad size and 3D interconnect pitch scaling, resulting in minimal electrical die-to-die interconnect delay. In this presentation we will discuss the properties of SiCN dielectrics as material of choice for hybrid bonding, as well as the process requirements for the mixed Cu/SiCN surface finish of wafers. Pitch scaling for hybrid bonding does not only require bonding overlay improvement, but as important is the ability of the Cu pad to expand and to make good connection to the opposite pad. The physical mechanisms of hybrid bonding and of Cu bulge out will be analyzed and compared to simulation data. Finally, the various improvements in wafer processing and wafer alignment during bonding will be discussed, resulting in high yield hybrid bonding down to 400nm interconnect pitch for wafer-to-wafer bonding. When applying this hybrid bonding technology to die-to-wafer bonding, additional challenges need to be addressed. Particularly challenging is maintaining the quality and cleanliness of the Cu/SiCN surface through die thinning, singulation and individual die pick & place operations. We discuss a process flow to enable the mitigation of these challenges, demonstrating 2 µm pitch die-to-wafer hybrid bonding.
Bio: Anne Jourdain received her PhD degree in Physics from University Joseph Fourier of Grenoble, France, in 1998. In 1999, she joined IMEC (Interuniversity Microelectronics Center) in Leuven, Belgium, to work on wafer-level-packaging solutions for RF-MEMS applications. In 2007, she joined the 3D Integration Research Program of IMEC to work on various wafer-to-wafer bonding and wafer thinning technologies. In 2019, she became responsible for the Backside Power Delivery Network integration activities within the program before taking the lead of the 3D Heterogeneous Integration team in 2022, looking at collective die-to-wafer and direct hybrid bonding technologies for 3D stacking applications. She is currently leading the Heterogeneous Integration and Packaging Development Group.

For other edited  videos from this symposium, visit  https://attend.ieee.org/hbs/?page_id=456