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Abstract Optoelectronics are crucial for developing energy‐efficient chip technology, with phase‐change materials (PCMs) emerging as promising candidates for reconfigurable components in photonic integrated circuits, such as nonvolatile phase shifters. Antimony sulfide (Sb2S3) stands out due to its low optical loss and considerable phase‐shifting properties, along with the non‐volatility of both phases. This study demonstrates that the crystallization kinetics of Sb2S3can be switched from growth‐driven to nucleation‐driven by altering the sample dimension from bulk to film. This tuning of the crystallization process is critical for optical switching applications requiring control over partial crystallization. Calorimetric measurements with heating rates spanning over six orders of magnitude, reveal that, unlike conventional PCMs that crystallize below the glass transition, Sb2S3exhibits a measurable glass transition prior to crystallization from the undercooled liquid (UCL) phase. The investigation of isothermal crystallization kinetics provides insights into nucleation rates and crystal growth velocities while confirming the shift to nucleation‐driven behavior at reduced film thicknesses—an essential aspect for effective device engineering. A fundamental difference in chemical bonding mechanisms was identified between Sb2S3, which exhibits covalent bonding in both material phases, and other PCMs, such as GeTe and Ge2Sb2Te5, which demonstrate pronounced bonding alterations upon crystallization.
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This content will become publicly available on July 1, 2026
PtCoO 2 for Scaled Interconnects
Copper (Cu) interconnects are an increasingly important bottleneck in integrated circuits due to energy consumption and latency caused by the notable increase in Cu resistivity as dimensions decrease, primarily due to electron scattering at surfaces. Herein, the potential of a directional conductor, PtCoO2, which has a low bulk resistivity and a distinctive anisotropic structure that mitigates electron surface scattering is showcased. Thin films of PtCoO2of various thicknesses are synthesized by molecular beam epitaxy (MBE) coupled with a postdeposition annealing process and the superior quality of PtCoO2films is demonstrated by multiple characterization techniques. The thickness‐dependent resistivity curve illustrates that PtCoO2significantly outperforms effective Cu (Cu with TaN barriers) and Ru in resistivity below 20.0 nm with a more than 6x reduction compared to effective Cu below 6.0 nm, having a value of only 6.32 μΩ cm at 3.3 nm. It is determined that grain boundary scattering can still be improved for even lower resistivities in this material system through a combination of experiments and theoretical simulations. PtCoO2is therefore a highly promising alternative material for future interconnect technologies promising lower resistivities, better stability, and significant improvements in energy efficiency and latency for advanced integrated circuits.
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- PAR ID:
- 10618552
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- Small Structures
- Volume:
- 6
- Issue:
- 7
- ISSN:
- 2688-4062
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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