A convenient method for electron tomography sample preparation using a focused ion beam

Area of Science:

• Materials Science
• Microscopy Techniques
• Nanotechnology

Background:

• Standard sample preparation for electron tomography faces challenges with projected sample thickness at high tilt angles.
• Focused Ion Beam (FIB) preparation can introduce gallium (Ga⁺) contamination, particularly for rod-shaped samples.

Purpose of the Study:

• To introduce a new sample preparation method for three-dimensional electron tomography.
• To overcome limitations of existing methods regarding sample thickness and contamination.
• To enable broader applicability of tomography for various sample types.

Main Methods:

• Utilizes standard film deposition techniques.
• Incorporates focused ion beam (FIB) milling.
• Specifically designed to mitigate issues arising from projected sample thickness at high tilt angles.

Main Results:

• Successfully reduced problems associated with projected sample thickness at high tilt angles.
• Enabled tomography sample imaging across a ±75° tilt range.
• Minimized Ga⁺ contamination compared to conventional FIB preparation of rod-shaped samples.
• Provided extended thin regions suitable for standard 2D projection analyses.

Conclusions:

• The developed method significantly improves sample preparation for three-dimensional electron tomography.
• The technique offers a wider tilt range and reduced contamination, enhancing data quality.
• This approach broadens the utility of electron tomography in practical applications.