Polarized holographic lithography system for high-uniformity microscale patterning with periodic tunability.

Area of Science:

• Optics and Photonics
• Materials Science
• Nanotechnology

Background:

• Periodic microscale array structures are crucial for photonic crystals and diffraction gratings.
• Fabricating high-uniformity two-dimensional (2D) crossed gratings with tunable periods presents a significant challenge.

Purpose of the Study:

• To propose and demonstrate a polarized holographic lithography system for patterning high-uniformity 2D crossed-grating structures.
• To achieve periodic tunability and control polarization states for enhanced interference fringe uniformity.

Main Methods:

• Utilizing orthogonal two-axis Lloyd's mirror interference and polarization modulation to generate three sub-beams.
• Employing a strict full polarization tracing model and a polarization modulation model to manage polarization states and interference intensities.
• Adjusting interferometer spatial positioning for flexible tuning of the 2D pattern period.

Main Results:

• Successfully patterned high-uniformity 2D crossed-grating structures with wavelength-comparable periods in a single exposure.
• Achieved flexible tuning of the 2D pattern period within a range of 500-1500 nm.
• Demonstrated control over polarization states to ensure desired interference intensities and eliminate unexpected interference.

Conclusions:

• The proposed polarized holographic lithography system is a promising approach for fabricating high-uniformity 2D crossed gratings.
• The rapid, stable, and period-tunable patterning method has potential applications in other multibeam interference lithography techniques.