Electrically Robust Single-Crystalline WTe₂ Nanobelts for Nanoscale Electrical Interconnects

As the elements of integrated circuits are downsized to the nanoscale, the current Cu-based interconnects are facing limitations due to increased resistivity and decreased current-carrying capacity because of scaling. Here, the bottom-up synthesis of single-crystalline WTe₂ nanobelts and low- and high-field electrical characterization of nanoscale interconnect test structures in various ambient conditions are reported. Unlike exfoliated flakes obtained by the top-down approach, the bottom-up growth mode of WTe₂ nanobelts allows systemic characterization of the electrical properties of WTe₂ single crystals as a function of channel dimensions. Using a 1D heat transport model and a power law, it is determined that the breakdown of WTe₂ devices under vacuum and with AlO _x capping layer follows an ideal pattern for Joule heating, far from edge scattering. High-field electrical measurements and self-heating modeling demonstrate that the WTe₂ nanobelts have a breakdown current density approaching ≈100 MA cm⁻², remarkably higher than those of conventional metals and other transition-metal chalcogenides, and sustain the highest electrical power per channel length (≈16.4 W cm⁻¹) among the interconnect candidates. The results suggest superior robustness of WTe₂ against high-bias sweep and its possible applicability in future nanoelectronics.