Page 43 - Chip Scale Review_November December_2021-digital

Summary
The feasibility of using hybrid
metal/graphene structures for sub-
2nm interconnect applications was
discussed. Two different structures were
examined: graphene-capped metal and
metal-capped graphene devices. In both
cases, the interfaces between graphene
and metal play a crucial role in the
overall electrical behavior of the hybrid
interconnect. While graphene-capped
metal interconnects are the most mature,
stacks of alternating layers may come
into play in the longer term. It should
finally be noted that the above study
focused on Ru as a metal of interest, a
material that has recently emerged as a
potential alternative for Cu metallization.
But the concepts presented here are
expected to be expandable towards other
“interconnect” metals.

References
1. C. Adelmann, et al., “Alternative
metals: from ab initio screening
to calibrated narrow line models,”
Proc. IEEE IITC 2018, pp.: 154-156
2. S. Ach ra, et al., “G raphene-
ruthenium hybrid interconnects,”
Proc. IEEE IITC 2019; To be
published.
3. S. Achra, et al., “Characterization
of interface interactions between
graphene and ruthenium,” Proc.
IEEE IITC 2020, pp.: 133-135
4. S. Achra, et al., “Metal induced
charge transfer doping in graphene-
ruthenium hybrid interconnects,”
Carbon 183 (2021) 999-1011.
5. S. Achra, et al, “Enhancing interface
doping in graphene-metal hybrid
devices using H2 plasma clean,”
Applied Surface Science 538 (2021)
148046.

Biographies
Swati Achra is pursuing a PhD in Materials Engineering in the MTM department, KU Leuven and at imec.
She joined the Nano-interconnects team at imec in 2017 and works on developing graphene-enabled hybrid
interconnects for future technology nodes. She received a joint MSc degree in Erasmus Mundus Masters in
Nanoscience and Nanotechnology magna cum laude from KU Leuven, Belgium and U. Grenoble Alpes, France in
2017. She graduated B.Tech in Chemical Engineering and Materials Science with a university gold medal in 2015
from Amrita Vishwa Vidyapeetham, Tamil Nadu, India. Email swatiachra92@gmail.com; swati.achra@imec.be

Inge Asselberghs is Program Manager for exploratory logic at imec, Leuven, Belgium. She received MSc and PhD degrees
in Chemistry from the U. of Leuven, Leuven, Belgium, in 1998 and 2003, respectively. After a Post-Doctoral Fellowship in
nonlinear optics, she moved to imec, Leuven, as a Researcher, where she was involved in exploratory 2-D-material-based device
fabrication and characterization.

41
Chip Scale Review November • December • 2021 [ChipScaleReview.com] 41