Positive and Negative Dual-Type Hafnium-Based Hybrid Dry Photoresist for Nanolithography

Area of Science:

• Materials Science
• Nanotechnology
• Semiconductor Manufacturing

Background:

• Traditional photoresist processing faces challenges in precise thickness control and pattern collapse, particularly for sub-20 nm features in high-NA EUV lithography.
• Solution-based methods struggle with limitations like capillary action during wet development, hindering the fabrication of ultra-thin films required for advanced nodes.

Purpose of the Study:

• To develop a high-resolution dry photoresist using a hafnium-based hybrid thin film.
• To investigate dual-type photoresist capabilities (positive and negative) using molecular layer deposition (MLD) and different development techniques.

Main Methods:

• Fabrication of a hafnium-based hybrid thin film using tetrakis(dimethylamido)hafnium (TDMAHf) and 2-buten-1,4-diol (BED) via MLD.
• Development of positive-type photoresist using inductively coupled plasma (ICP) dry etching.
• Development of negative-type photoresist using 15% tetramethylammonium hydroxide (TMAH) wet development.
• Resolution testing using electron beam exposure at 25 keV and 50 keV.

Main Results:

• Achieved a sensitivity of 2400 μC/cm² at 25 keV electron beam exposure.
• Demonstrated a resolution of 20 nm for dry development at 50 keV.
• Achieved a resolution of 7 nm for wet development at 50 keV.

Conclusions:

• The developed hafnium-based hybrid photoresist exhibits significant potential for advanced lithography applications.
• This research provides a foundation for developing superior dry photoresist technologies, addressing critical challenges in semiconductor miniaturization.