Spatial modulation of nanopattern dimensions by combining interference lithography and grayscale-patterned secondary...

Area of Science:

• Nanotechnology
• Lithography
• Materials Science

Background:

• Functional nanostructures are vital for plasmonics, metasurfaces, and biosensors.
• Current nanopatterning methods face challenges in large-area, arbitrary feature size control due to low throughput.

Purpose of the Study:

• To develop a wafer-scale lithographic approach for arbitrary modulation of nanostructure feature size distribution.
• To overcome limitations of existing low-throughput nanopatterning techniques.

Main Methods:

• Integration of interference lithography (IL) with grayscale-patterned secondary exposure (SE).
• Utilizing SE to spatially modulate photoresist nanostructure dimensions after high-throughput IL.
• Employing grayscale-patterned SE to correct linewidth variations from IL's Gaussian laser beam profile.

Main Results:

• Fabrication of 4-inch wafer-scale nanogratings with uniform linewidths (<5% variation).
• Demonstration of wafer-scale structural color painting by spatially modulating the filling ratio using SE.
• Achieved gradient grayscale color through precise feature size modulation.

Conclusions:

• The combined IL and SE approach offers a high-throughput, scalable solution for precise nanostructure fabrication.
• This technique enables arbitrary control over feature size distribution for diverse nanophotonic applications.
• The method is effective for both uniform nanogratings and complex patterns like structural color.