Turing-patterned Ta₂S₃ enables sub-2 nm diffusion barrier for advanced Cu interconnects.

Area of Science:

• Materials Science
• Nanotechnology
• Semiconductor Physics

Background:

• Back-end-of-line (BEOL) interconnects face scaling limitations due to conventional barrier/liner materials like TaN/Ta(Co).
• Shrinking pitch sizes exacerbate resistance-capacitance (RC) delay, hindering advanced integrated circuit performance.

Purpose of the Study:

• To introduce a novel thin barrier material for advanced semiconductor interconnects.
• To address the limitations of existing barrier technologies in next-generation integrated circuits.

Main Methods:

• Synthesis of Turing-patterned tantalum sulfide (Tp-Ta2S3) using an energy-enhanced atomic layer deposition (ALD) process.
• Characterization of the Tp-Ta2S3 barrier's morphology, adhesion, wettability, and copper diffusion barrier properties.

Main Results:

• The synthesized Tp-Ta2S3 exhibits a unique labyrinthine stripe morphology with an intertwined layer structure.
• A 1.2 nm thick Tp-Ta2S3 barrier demonstrates excellent copper wettability and adhesion.
• Tp-Ta2S3 shows significantly enhanced copper diffusion barrier performance compared to state-of-the-art TaN barriers.

Conclusions:

• Turing-patterned Ta2S3 is a promising alternative for advanced BEOL interconnects.
• The unique morphology of Tp-Ta2S3 enhances copper diffusion blocking by increasing migration path length.
• This breakthrough material can mitigate RC delay and enable further scaling in integrated circuits.