TEM sample preparation by FIB for carbon nanotube interconnects

Area of Science:

• Materials Science
• Nanotechnology
• Electron Microscopy

Background:

• Transmission electron microscopy (TEM) is crucial for studying carbon nanotubes (CNTs).
• High-quality TEM samples are essential for analyzing CNTs in patterned substrates for interconnects.
• Current preparation methods can struggle to preserve CNT integrity.

Purpose of the Study:

• To evaluate focused ion beam (FIB) as a method for preparing TEM samples of CNTs within patterned substrates.
• To demonstrate the preservation of CNT inner shell structure using FIB preparation.

Main Methods:

• Focused ion beam (FIB) milling was employed to prepare TEM lamellae from patterned substrates with grown CNTs.
• A dual-cap platinum (Pt) protection layer was applied.
• An extensive 5 kV cleaning procedure was utilized during milling.

Main Results:

• TEM specimen preparation using FIB successfully yielded lamellae containing CNTs within contact holes.
• The inner shell structure of the carbon nanotubes was preserved during the FIB milling process.
• The applied protection layer and cleaning procedure prevented sample deterioration.

Conclusions:

• Focused ion beam (FIB) is a viable and effective technique for preparing high-quality TEM samples of carbon nanotubes (CNTs).
• This method enables detailed structural analysis of CNTs for potential interconnect applications.
• FIB preparation ensures the integrity of CNTs, crucial for understanding their performance.