Norbornene and Epoxide-Substituted Silsesquioxane Photoresists with High-Sensitivity and Stability

Area of Science:

• Materials Science
• Nanotechnology
• Chemistry

Background:

• Extreme ultraviolet (EUV) lithography demands advanced photoresists for sub-20 nm pattern fidelity.
• Hydrogen silsesquioxane (HSQ) faces challenges in EUV applications due to instability and low sensitivity.

Purpose of the Study:

• To develop novel partially alkyl-substituted silsesquioxane (PASS) resists to address HSQ limitations.
• To enhance photoresist performance for high-resolution lithography.

Main Methods:

• Integration of photoacid generator (PAG) into PASS resist formulations.
• Lithographic performance evaluation using electron beam lithography.
• Characterization using micro-Raman spectroscopy and model compound studies.

Main Results:

• Achieved 14 nm resolution with 1.3 nm line edge roughness.
• Demonstrated high sensitivity (4.3 μC/cm²) and contrast (5.1).
• Exhibited a 360-day gelation period and 160-fold improvement in stability over HSQ.

Conclusions:

• PAG integration enhances PASS resist sensitivity and shelf stability via dual mechanisms.
• PASS resists are viable candidates for EUV lithography in semiconductor nanofabrication.
• Structural tunability of PASS resists supports diverse nanomanufacturing applications.