Efficient Self-Contained Photoacid Generator System Based on Photochromic Terarylenes

Area of Science:

• Organic Chemistry
• Photochemistry
• Materials Science

Background:

• Photoacid generators (PAGs) are crucial in photolithography.
• Developing highly efficient and sensitive PAGs is an ongoing research area.
• Terarylene-based PAGs offer unique photochemical properties.

Purpose of the Study:

• To synthesize and characterize novel neutral photoacid generators based on photochromic terarylenes.
• To investigate the effect of structural modifications on the quantum yield (QY) of acid generation.
• To evaluate the performance of a mesylic acid-releasing PAG as a photocatalyst.

Main Methods:

• Synthesis of terarylene-based compounds with modified hetero-aromatic moieties (thiazolyl and thienyl groups).
• Photochemical studies to determine quantum yields for acid generation under varying conditions (solvents, acid source).
• Evaluation of PAG performance in a chemically amplified positive resist system.

Main Results:

• Novel terarylene-based PAGs were successfully prepared.
• Quantum yields for acid generation reached up to 0.6 and 0.7 with structural modifications.
• Aromatic leaving groups were found to decrease photoefficiency.
• The mesylic acid-releasing PAG demonstrated photocatalytic activity in a resist system.

Conclusions:

• Structural modifications of terarylene-based PAGs significantly enhance acid generation efficiency.
• Optimized PAGs show high quantum yields, suitable for advanced photolithography.
• These PAGs represent promising photocatalysts for chemically amplified resist applications.