4X reduction extreme ultraviolet interferometric lithography

Area of Science:

• Nanotechnology
• Materials Science
• Physics

Background:

• Interferometric lithography is crucial for fabricating nanoscale patterns.
• Traditional methods face challenges in mask resolution and feature size reduction.
• Extreme ultraviolet (EUV) lithography offers high resolution for microchip fabrication.

Purpose of the Study:

• To report initial results of a 4X reduction interferometric lithography technique.
• To demonstrate a simplified mask fabrication process for high-resolution gratings.
• To achieve sub-20 nm grating patterns using EUV radiation.

Main Methods:

• Utilized a 4X reduction interferometric lithography setup with extreme ultraviolet (EUV) radiation.
• Employed 2nd diffraction orders instead of 1st orders for fringe generation.
• Exposed a hydrogen silsesquioxane photoresist with a 13.4 nm wavelength EUV source.

Main Results:

• Successfully recorded interferometric fringes reduced by 4X, from 70 nm to 17.5 nm half-period gratings.
• Demonstrated simplified mask fabrication requirements due to the use of 2nd diffraction orders.
• Achieved high-resolution pattern formation in a 50 nm thick photoresist layer.

Conclusions:

• The 4X reduction interferometric lithography technique offers a viable path to simplified, high-resolution pattern fabrication.
• This method is promising for advancing semiconductor manufacturing and nanotechnology applications.
• The use of 2nd diffraction orders in EUV interferometric lithography is effective for achieving smaller feature sizes.