Printing sub-micron structures using Talbot mask-aligner lithography with a 193 nm CW laser light source

Area of Science:

• Materials Science
• Optical Engineering
• Nanotechnology

Background:

• Mask-aligner lithography requires continuous resolution improvements for shrinking feature sizes in back-end processes.
• The Talbot effect offers a promising approach for fabricating periodic structures in lithography.

Purpose of the Study:

• To demonstrate the fabrication of sub-micron periodic arrays in silicon substrates using the Talbot effect combined with a 193 nm continuous wave laser.
• To investigate the capabilities of this novel lithography system for proximity printing.

Main Methods:

• Utilizing the Talbot effect with a continuous wave laser source at 193 nm.
• Performing proximity printing experiments with simulations and experimental validation.
• Analyzing prints up to the fourth Talbot plane.

Main Results:

• Successful fabrication of periodic arrays in silicon substrates with sub-micron feature sizes.
• Demonstrated efficient beam shaping and reduced minimum feature size due to the laser's coherence and brilliance.
• Achieved high-resolution prints at a fixed gap of 20 µm.

Conclusions:

• The combination of the Talbot effect and a 193 nm continuous wave laser is effective for sub-micron periodic array fabrication.
• This printing technology is suitable for manufacturing optical metasurfaces, bio-sensor arrays, membranes, and microchannel plates.