Sub-60 nm periodic grating feature patterning by immersion based 364 nm laser interference

Area of Science:

• Nanofabrication and Lithography
• Optical Engineering
• Materials Science

Background:

• Achieving high-resolution periodic structures is crucial for advanced optical and electronic devices.
• Conventional lithography methods face limitations in achieving sub-60 nm feature sizes.
• Interferometric lithography offers a pathway to overcome these resolution limits.

Purpose of the Study:

• To develop and demonstrate a methodology for fabricating high-resolution periodic grating features.
• To achieve feature sizes below 60 nm using a specific interferometric setup.
• To explore the capabilities of high-index prism-based interferometry for advanced patterning.

Main Methods:

• Utilized a high-index prism (refractive index 1.939) based interferometer.
• Employed an i-line laser source for illumination.
• Fabricated features on i-line resist in an immersion medium.

Main Results:

• Successfully fabricated periodic grating features with sub-60 nm half pitch size.
• Demonstrated the effectiveness of the high-index prism interferometer for high-resolution patterning.
• Validated the methodology for creating nanoscale features in resist.

Conclusions:

• The reported methodology enables the fabrication of ultra-high resolution periodic gratings.
• High-index prism interferometry combined with immersion lithography is a viable technique for sub-60 nm patterning.
• This approach has significant implications for next-generation microdevice manufacturing.