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Abstract Electromigration in metal interconnects remains a significant challenge in the continued scaling of integrated circuits towards ever‐smaller single‐nanometer nodes. Conventional damascene architectures of barrier/liner layers and conducting metal cause inevitable compromises between device performance and feature dimensions. In contrast to contemporary barrier/liner materials (e.g., Co, Ta, and Ru), an ultrathin passivation layer that can effectively mitigate electromigration is needed. At the ultimate atomically‐thin limit, 2D materials are promising candidates given their exceptional mechanical properties and impermeability. Here, a facile and effective approach is presented to mitigating electromigration in copper (Cu) interconnects via passivation with insulating monolayer 2D hexagonal boron nitride (hBN). The hBN‐passivated Cu interconnects, compared to otherwise identical but bare Cu interconnects, exhibit on average a >20% higher breakdown current density and a >2600% longer lifetime (at a high current density of 5.4 × 107A cm−2). Post‐mortem metrology elucidates uniform conformal contact between the hBN‐passivated Cu interface and common failure features due to electromigration.
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Resistivity scaling of porous MoP narrow lines
The resistivity scaling of copper (Cu) interconnects with decreasing dimensions remains a major challenge in the downscaling of integrated circuits. Molybdenum phosphide (MoP) is a triple-point topological semimetal (TSM) with low resistivity and high carrier density. With the presence of topologically protected surface states that should be defect-tolerant and electron backscatter forbidden, MoP nanowires have shown promising resistivity values compared to Cu interconnects at the nanometer scale. In this work, using template-assisted chemical vapor conversion and standard fabrication techniques that are industry-adoptable, we report the fabrication of porous but highly crystalline MoP narrow lines with controlled sizes and dimensions. We examine the influence of porosity, thickness, and cross-section area on the resistivity values of the fabricated MoP lines to further test the feasibility of MoP for interconnect applications. Our work presents a facile approach to synthesizing TSM nanowires with different dimensions and cross sections, enabling experimental investigations of their predicted unconventional resistivity scaling behavior. Finally, our results provide insight into the effects of porosity on the resistivity of these materials on the nanometer scale.
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- Award ID(s):
- 2025233
- PAR ID:
- 10595121
- Publisher / Repository:
- American Institute of Physics
- Date Published:
- Journal Name:
- APL Materials
- Volume:
- 12
- Issue:
- 12
- ISSN:
- 2166-532X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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