Trinuclear Tin Complexes for Advanced Lithography: Sensitivity Enhancement via the Synergistic Effect in Dual...

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Extreme ultraviolet (EUV) lithography faces challenges in balancing nanoscale pattern fidelity with high sensitivity.
• Organotin-based trinuclear macrocyclic complexes offer potential for improved EUV photoresist performance.
• Photon shot noise can lead to roughness in lithographic patterns.

Purpose of the Study:

• To investigate the effect of organic groups on the sensitivity of trinuclear tin complex photoresists.
• To evaluate the performance of specific trinuclear tin complexes in high-resolution patterning.
• To elucidate the mechanism behind the enhanced sensitivity of Vi-Sn-Oc.

Main Methods:

• Synthesis and characterization of four trinuclear tin complexes with varying organic groups.
• Evaluation of photoresist sensitivity using electron beam lithography (EBL) and EUV lithography.
• Mechanistic studies on radiation exposure to understand solubility changes and cross-linking behavior.

Main Results:

• The Vi-Sn-Oc complex, featuring C═C bonds and long alkyl groups, demonstrated excellent sensitivity (D0 = 23 μC/cm²) and high-resolution patterning (16 nm lines via EBL, 20 nm lines via EUV).
• Trinuclear tin complexes successfully achieved nanoscale pattern fidelity at high sensitivity.
• Mechanistic studies revealed a synergistic dual cross-linking system (Sn-X-Sn and C═C) as the source of Vi-Sn-Oc's enhanced sensitivity.

Conclusions:

• Trinuclear tin complexes are effective in achieving high sensitivity and nanoscale pattern fidelity in EUV lithography.
• The Vi-Sn-Oc complex represents a promising material for advanced photoresist applications.
• The identified synergistic cross-linking mechanism provides a new pathway for developing next-generation high-sensitivity, high-resolution tin-oxide EUV photoresists.