Circular multilayer zone plate for high-energy x-ray nano-imaging

Area of Science:

• Optics and Photonics
• Materials Science
• X-ray Microscopy

Background:

• Multilayer zone plates (MZPs) are advanced diffractive optical elements for focusing radiation.
• Achieving high resolution with MZPs requires precise control over layer interfaces and material properties.

Purpose of the Study:

• To fabricate and evaluate the focusing performance of a circular multilayer zone plate (MZP) for 20-keV x-rays.
• To assess the potential of the MZP for achieving diffraction-limited resolution.

Main Methods:

• Fabrication of a circular MZP using alternating MoSi(2) and Si layers deposited by DC magnetron sputtering on a wire core.
• Evaluation of focusing performance using 20-keV x-rays.
• Conversion of measured line spread function to point spread function via tomographic reconstruction.

Main Results:

• The fabricated MZP interfaces satisfied the Fresnel zone condition.
• The MZP demonstrated the potential for diffraction-limited resolving power, calculated at 35 nm.
• Scanning transmission microscopy utilizing the MZP successfully resolved a 50-nm line-and-space pattern.

Conclusions:

• The developed circular MZP shows significant promise for high-resolution x-ray imaging.
• The fabrication method and material choices are suitable for achieving sub-50 nm resolution with MZPs.
• Further development could lead to MZPs enabling diffraction-limited resolution in x-ray microscopy.