A correlation between polymer molecular structure and acid catalyzed kinetics is demonstrated by a binary copolymer photoresists system which includes an acid-liable and an acid-inert species. It was found that the acid catalyzed deprotection kinetics significantly depends on the non-reactive comonomer in the polymer chain, i.e. the apparent reaction rate constant monotonically decreases as this comonomer composition is increased. The phenomena are interpreted as the reduction of diffusivity of photoacid in the polymer matrix through its hydrogen bonding interaction with the polar group in the inert comonomer. Additionally, the hydrogen bonding interaction existing between photoacid and reaction byproduct is expected to be the main reason to account for the acid loss or trapping effect observed by various researchers.
Proceedings Title: Proceedings of SPIE
Conference Dates: February 19-24, 2006
Conference Location: San Jose, CA
Conference Title: SPIE Advanced Lithography
Pub Type: Conferences
copolymer, diffusion, fourier transform infrared spectroscopy, photoacid, photolithography, photoresists, reaction rate constant