A method for producing site-specific TEM specimens from low contrast materials with nanometer precision

Area of Science:

• Materials Science
• Microscopy
• Nanotechnology

Background:

• Transmission Electron Microscopy (TEM) requires high-quality specimens.
• Extracting specimens from low-contrast materials using Focused Ion Beam (FIB) milling presents significant challenges.
• Existing methods often lack precision or require specialized equipment.

Purpose of the Study:

• To develop a high-precision method for TEM specimen extraction.
• To overcome challenges associated with low-contrast materials in FIB milling.
• To provide a generally applicable technique for producing high-quality TEM samples.

Main Methods:

• Developed a technique to create high-contrast markers adjacent to the area of interest.
• Markers are filled during the deposition of a protective layer.
• Utilized either Platinum (Pt) or Carbon (C) for markers based on optimal contrast.

Main Results:

• Successfully enabled precise identification of the area of interest during FIB milling.
• Ensured accurate extraction of TEM specimens at desired locations.
• Demonstrated applicability across three diverse material types.

Conclusions:

• The developed marker-based method significantly enhances precision in TEM specimen preparation.
• This technique is broadly applicable to FIB/Scanning Electron Microscope users for low-contrast materials.
• High-quality TEM specimens can be prepared from small features without specialized holders.