Electrically Robust Single-Crystalline WTe₂ Nanobelts for Nanoscale Electrical Interconnects

Area of Science:

• Materials Science
• Nanotechnology
• Solid State Physics

Background:

• Current copper-based interconnects in integrated circuits face limitations at the nanoscale due to increased resistivity and reduced current-carrying capacity.
• Scaling down integrated circuit elements necessitates the exploration of novel materials for interconnects that can overcome these limitations.

Purpose of the Study:

• To report the bottom-up synthesis of single-crystalline tungsten ditelluride (WTe2) nanobelts.
• To perform electrical characterization of nanoscale WTe2 interconnects under various ambient conditions.
• To evaluate the potential of WTe2 as a future nanoelectronic interconnect material.

Main Methods:

• Bottom-up synthesis of single-crystalline WTe2 nanobelts.
• Low- and high-field electrical characterization of nanoscale interconnect test structures.
• Analysis using a 1D heat transport model and power law to understand breakdown mechanisms.
• Self-heating modeling to assess device performance under high electrical stress.

Main Results:

• WTe2 nanobelts exhibit breakdown behavior consistent with ideal Joule heating, independent of edge scattering.
• Demonstrated a breakdown current density approaching 100 MA cm⁻², significantly higher than conventional metals.
• Achieved the highest electrical power per channel length (≈16.4 W cm⁻¹) among evaluated interconnect candidates.

Conclusions:

• WTe2 nanobelts show superior robustness against high-bias sweeps compared to existing interconnect materials.
• The exceptional electrical properties suggest WTe2's significant potential for future nanoelectronic applications.
• Bottom-up synthesis enables systematic characterization of WTe2 electrical properties as a function of dimensions.