Direct-write X-ray lithography using a hard X-ray Fresnel zone plate

Area of Science:

• Physics
• Materials Science
• Nanotechnology

Background:

• Advanced lithography techniques are crucial for fabricating nanoscale devices.
• X-ray lithography offers potential for high resolution due to short wavelengths.

Purpose of the Study:

• To demonstrate direct-write X-ray lithography with nanoscale resolution.
• To investigate factors influencing pattern fidelity in hard X-ray lithography.

Main Methods:

• Utilized a hard X-ray beam (7.5 keV) focused by a Fresnel zone plate (40 nm outermost zone width).
• Employed direct-write patterning on photoresist thin films.
• Analyzed pattern dimensions and their dependence on substrate properties.

Main Results:

• Achieved a resolution better than 25 nm for arbitrary patterns.
• Observed significant dependence of pattern dimension on the underlying substrate due to electron scattering.
• Identified proximity effects from diffuse scattering and electron blur.

Conclusions:

• Direct-write hard X-ray lithography is a viable method for nanoscale patterning.
• Substrate interactions and scattering effects must be managed for optimal resolution.
• The technique shows promise for future high-resolution lithographic applications.