Coupled Electromagnetic and Reaction Kinetics Simulation of Super-Resolution Interference Lithography

Area of Science:

• Nanofabrication and Materials Science
• Optical Engineering
• Chemical Kinetics

Background:

• Super-resolution microscopy overcomes diffraction limits.
• Two-color interference lithography achieves nanopatterning via nonequilibrium kinetics.
• Extending nanopatterning to bulk materials requires understanding optical-chemical dynamics.

Purpose of the Study:

• To develop a computational approach for simulating coupled optical and chemical kinetics in two-color interference lithography.
• To enable the design of high-precision nanopatterns in thick films.

Main Methods:

• Developed an efficient electromagnetic perturbation theory for fully coupled simulations.
• Applied the method to a spirothiopyran-functionalized photoresist system.
• Investigated diffraction, absorption, and reaction kinetics.

Main Results:

• Simulations show negligible (<0.1%) diffraction and absorption effects in films up to 10 μm.
• Tuning exposure parameters achieved up to 80% concentration contrast.
• Evaluated sequential and multiplexed exposure strategies for pattern pitch reduction.

Conclusions:

• The developed simulation approach accurately predicts coupled dynamics for two-color interference lithography.
• This facilitates computational design for precise nanopatterning in bulk materials.
• Enables scalable, high-resolution nanopatterning with visible light.