Collapse behavior and forces of multistack nanolines

Area of Science:

• Materials Science
• Nanotechnology
• Mechanical Engineering

Background:

• Multistack nanolines (MNLs) are crucial components in microelectronic devices.
• Understanding their mechanical properties, particularly collapse behavior, is essential for device reliability.
• Previous studies have not fully elucidated the relationship between MNL composition and collapse mechanics.

Purpose of the Study:

• To investigate and compare the collapse force and behavior of two distinct MNL structures.
• To determine the influence of material composition and interfaces on MNL mechanical failure.
• To establish the relationship between MNL linewidth and collapse force.

Main Methods:

• Utilized atomic force microscopy (AFM) to apply controlled forces to MNLs.
• Fabricated two types of MNLs: Si/siliconoxynitride/amorphous Si/SiO(2) and Si/SiO(2)/polycrystalline Si/SiO(2).
• Analyzed fracture patterns and measured collapse forces as a function of MNL linewidth.

Main Results:

• The Si/SiON/a-Si/SiO(2) MNL exhibited larger fragment lengths at lower collapse forces, indicating a softer material.
• The Si/SiO(2)/poly-Si/SiO(2) MNL showed smaller fragment lengths at higher collapse forces, signifying a harder material.
• Collapse force demonstrated a quadratic relationship with linewidth for both MNL types.
• Failure mechanisms differed: softer MNLs delaminated and fractured sequentially, while harder MNLs fractured simultaneously at both ends.

Conclusions:

• The mechanical strength and adhesion forces at material interfaces significantly dictate MNL collapse behavior.
• MNL composition (amorphous vs. polycrystalline silicon) critically influences its mechanical response and failure mode.
• The findings provide valuable insights for designing robust nanoline structures with predictable mechanical reliability.