Page 15 - Chip Scale Review_November-December_2023-digital

The importance of cleanliness was clearly
stated and demonstrated via studies
showing void formations arising from
particle entrapment. The bonding process
itself was accomplished with advanced
dynamic die-shaping capabilities, state of
the art alignment (162nm @ 3σ), and using
inline control capability. Finally, control of
the queue time along the whole process is
critical to guarantee optimal yield.

Acknowledgments
Portions of this article were presented
at the IMAPS Device Conference 2023.
Additional co-authors are: Ying Wang,
Raymond Hung, Yauloong RuiPing
Wang, Arvind Sundarrajan of Applied
Materials, Inc., Hybrid Bonding Centre of
Excellence; and Stefan Schmid, Benedikt
Auer, Djuro Bikaljevic, PC Koay,
Nithyananda Hegde, and Chris Scanlan of
BE Semiconductor Industries N.V.

References
1. W. L. I. C. C. a. C. H. Chiu, “Low-
Figure 12: IR overlay for die placement on a wafer with direct bonding including a copper pad. temper at u re wafer-to -wafer
hybrid bonding by nanocrystalline
indicate that actual bond placement trials with optimizations are planned in the copper,” IEEE 72nd Elec. Comp.
accuracy is an impressive 160nm @ ±3s for future. The data shown in Figure 12 was and Tech. Conf. (ECTC), 2022.
worst corner, which is currently one of the collected with an inline metrology system 2. R. Agarwal, et al., “3D packaging
best die-to-wafer (D2W) accuracies. The with feedback control capability. for heterogeneous integration,”
green circle represents a ±200nm circle. 72nd ECTC, 2022.
For the second scenario, the wafers were Summary 3. S. Sitaraman, et al., ”A holistic
subjected to wet cleaning and plasma, A working process flow for D2W HB development framework for hybrid
as delineated in Figure 1. The dies in has been presented. Positive outcomes of bonding,” 72nd ECTC 2022.
question were ~6x6mm. Figure 12 shows an HVM-capable process heavily depend 4. V. Chidambaram, et al., ”Dielectric
placement accuracy results of 316nm @ on the co-optimization of many pieces of materials characterization for
±3s for worst corner. The main factor for a complex technical jigsaw. The bonding hybrid bonding,” IEEE 71st ECTC,
the gap in accuracy is that direct bonding dielectric needs to be controlled in terms San Diego, CA, USA, 2021.
is more prone to impact from customer of surface roughness, and needs to be 5. “https://www.azom.com/properties.
material than any other bonding mechanism properly activated with plasma. Such aspx?ArticleID=1114,” [Online].
such as mentioned in the first part of this plasma should not lead to damage to the 6. S. Son, et al., “Characteristics of
article due to its complexity and stringent dielectric, nor to the metal pads, which, plasma-activated dielectric film
requirements. Notwithstanding, 316nm in turn need to be controlled not just in surfaces for direct wafer bonding,”
@ ±3s for worst corner is still a very good terms of dishing, but also with regard to IEEE 70th ECTC, 2020.
result for a lab test vehicle and further unwanted protrusions from the Ta barrier.

Biographies
Jonathan Abdilla is Director of Technical Marketing at BE Semiconductor Industries (BESI) N. V., Austria.
He has 17 years of packaging experience in the semiconductor industry. Before joining BESI, he worked
for STMicroelectronics. He has participated in several EU-funded projects and resides on several technical
committees for semiconductor packaging conferences. He has a degree in Mechanical Engineering and an
Executive MBA from the U. of Malta and a diploma in Computing Information Systems from the U. of London.
Email jonathan.abdilla@besi.com

Guan Huei See is Director of Packaging Process Integration at the Hybrid Bonding Centre of Excellence at Applied Materials
Singapore Technologies Pte Ltd. He spent the last 8 years enabling advanced packaging process integration solutions, where
hybrid bonding (HB) is the most essential. This role requires him to generate and identify the necessary conditions to achieve
successful C2W HB and readiness for high-volume manufacturing production.

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