arXiv subjects

Gyungho Maeng

Publications and source records attributed to Gyungho Maeng.

4 recordsLinked to original sources

arXiv2026

Role of surface states and band modulations in ultrathin ruthenium interconnects

Mitigating the RC delay from transistor miniaturization is essential for next-generation devices, driving a focus on interconnect electrical performance. Current copper-based interconnects face a critical challenge, that their resistivity sharply increases at the nanometer-scale due to surface and grain boundary scattering. Therefore, there is a pressing need for techniques that reduce resistance in ultrathin metal films. In this study, we employ the density functional theory to investigate how the intrinsic electronic structure of thin films impacts conductivity as a function of thickness. Notably, our analysis of ruthenium slab structures shows that surface states significantly influence thickness-dependent resistivity. It reveals that vacuum-terminated Ru slab exhibits decreasing resistivity with the decrease in thickness, whereas oxygen-terminated Ru slab shows the opposite trend. This difference is fundamentally attributed to the presence or absence of surface states, highlighting the importance of surface engineering in optimizing interconnect performance.

cond-mat.mtrl-sci↗

arXiv2026

First-principles high-throughput screening of ruthenium compounds for advanced interconnects

As interconnect dimensions continue to shrink, the industry-standard copper faces a critical increase in resistivity, presenting a significant hurdle to overall device performance. To overcome this limitation, this work investigates the potential of ruthenium (Ru)-based compounds, encompassing binary, ternary, and quaternary systems, as viable alternatives to copper (Cu). Ruthenium is regarded as a strong candidate, owing to its inherent advantages in reliability and more favorable resistivity scaling at reduced dimensions. Moreover, forming compounds offers an effective strategy to engineer novel properties, expanding the material design space beyond the constraints of pure metals. Utilizing a high-throughput screening methodology, we systematically investigated a broad spectrum of 2,106 Ru-based compounds to identify candidates with superior electronic transport and reliability characteristics. Consequently, we successfully identified a total of 61 promising candidates that exhibit excellent resistivity scaling behavior and enhanced reliability. These findings demonstrate that Ru-based compounds offer a viable pathway to overcome the scaling limitations of next-generation interconnects.

cond-mat.mtrl-sci↗

arXiv2026

Cobalt Binary Compounds for Advanced Interconnect Materials

The industrial standard copper (Cu) interconnects face a substantial resistivity increase at thinner linewidths, posing a well-known challenge to limit overall device performance. To address this issue, we have evaluated the potential properties of cobalt (Co) based binary compounds as replacements for Cu. Co is considered as a promising alternative due to its potential for enhanced reliability and low resistivity at sub-nanoscale dimensions. Furthermore, the combination of elements provides a possibility to engineer novel properties, transcending the limitations of elemental metals and expanding the search space for next-generation interconnects. In this study, a high-throughput screening method was used to identify several Co-based binary compounds with superior electronic transport and reliability at reduced thickness. The findings demonstrate that specific Co-based binary compounds hold significant potential to overcome the performance limitations of scaled interconnects.

cond-mat.mtrl-sci↗

arXiv2026

Validation of constant mean free path and relaxation time approximations for metal resistivity: explicit treatment of electron-phonon interactions

The figure of merit $\rho \lambda$ the product of resistivity and mean free path (MFP) evaluated from first-principles calculations, is widely adopted to screen promising interconnect metals with high electrical conductivity at ultranarrow dimensions. However, the $\rho \lambda$ has been calculated without addressing the validity of the assumption that the MFP is independent of the wavevector $\mathbf{k}$. Here, we assess the validity of the constant MFP approximation, by estimating the $\mathbf{k}$-dependent MFPs for (an)isotropic elemental metals, with explicit treatment of electron-phonon interactions. Additionally, we verify the validity of the constant relaxation time approximation (CRTA) for resistivity calculations. We show that both the constant MFP approximation and CRTA are reasonable even for highly anisotropic Fermi surfaces. Our results support the practical use of those approximations in transport studies, where explicit electron-phonon calculations are not feasible.

cond-mat.mtrl-sci↗