Computational proximity lithography with extreme ultraviolet radiation.

Area of Science:

• Nanotechnology
• Lithography
• Optics

Background:

• Fabricating arbitrary nanoscale patterns is crucial for advanced electronics and photonics.
• Conventional lithography techniques often require complex and expensive high-resolution imaging optics.
• Existing methods struggle with printing non-periodic structures efficiently.

Purpose of the Study:

• To investigate the potential of extreme ultraviolet (EUV) computational proximity lithography for fabricating arbitrary nanoscale patterns.
• To propose and evaluate a novel holographic mask approach for EUV lithography.
• To assess the imaging performance of this method under different spatial coherence conditions.

Main Methods:

• Utilized a holographic mask (attenuating phase shifting mask) with two phase levels.
• Designed the mask for a 13.5 nm wavelength using a 50 nm pixel size electron beam resist.
• Evaluated imaging performance using EUV radiation from both synchrotron undulator and laboratory plasma sources with varying spatial coherence.

Main Results:

• Demonstrated the feasibility of fabricating arbitrary, non-periodic nanoscale patterns.
• The holographic mask approach successfully printed patterns without high-resolution imaging optics.
• Imaging performance was assessed using different EUV radiation sources and coherence levels.

Conclusions:

• EUV computational proximity lithography with holographic masks offers a promising route for arbitrary nanoscale pattern fabrication.
• This method eliminates the requirement for complex imaging optics, potentially reducing fabrication costs.
• The technique shows potential for diverse applications in nanotechnology and semiconductor manufacturing.