Position-controlled marker formation by helium ion microscope for aligning a TEM tomographic tilt series

Area of Science:

• Materials Science
• Microscopy
• Nanotechnology

Background:

• Accurate 3D image reconstruction in transmission electron microscopy (TEM) requires precise alignment of tomographic tilt series.
• Traditional alignment methods can be challenging, especially for complex or rod-shaped specimens.

Purpose of the Study:

• To develop and evaluate a novel method for creating fiducial markers for TEM tomography.
• To utilize a helium ion microscope (HIM) for fabricating precisely positioned nano-dots on specimens.

Main Methods:

• Nano-dots were fabricated using a helium ion microscope (HIM) with a gas injection system.
• The HIM's position controllability allowed for efficient and precise placement of nano-dots on a rod-shaped specimen.
• Nano-dot size was controlled by adjusting the beam radiation time.

Main Results:

• Successfully fabricated nano-dots with controlled sizes and positions on a rod-shaped specimen.
• Demonstrated the potential of these nano-dots as markers for aligning TEM tomographic tilt series.
• The HIM enabled efficient marker placement, overcoming limitations of previous techniques.

Conclusions:

• Helium ion microscopy offers a viable and efficient method for creating nano-dot fiducial markers.
• These nano-dot markers can significantly improve the alignment process for TEM tomography.
• This technique facilitates more accurate 3D image reconstruction, particularly for challenging sample geometries.