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Negative‐type photosensitive polyimide precursors developable with aqueous alkaline solutions
Author(s) -
Kikkawa H.,
Shoji F.,
Tanaka J.,
Kataoka F.,
Satou H.
Publication year - 1993
Publication title -
polymers for advanced technologies
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.61
H-Index - 90
eISSN - 1099-1581
pISSN - 1042-7147
DOI - 10.1002/pat.1993.220040407
Subject(s) - aqueous solution , solvent , materials science , polyimide , monomer , polymer chemistry , polymer , photoresist , diamine , benzophenone , photosensitivity , chemical engineering , ketone , organic chemistry , chemistry , composite material , layer (electronics) , optoelectronics , engineering
New photosensitive polyimide precursors developable with aqueous alkaline solutions were synthesized. Among diamine monomers having a photofunctional group, 2′‐(methacryloyloxy)ethyl 3,5‐diaminobenzoate yields high molecular weight polyamic acid. A photosensitive polymer composition consisting of Michler's ketone and a thermally stable peroxide, 3,3′,4,4′‐tetrakis(t‐butyldioxycarbonyl)benzophenone, results in a high photosensitivity of 200 J/m 2 . The photosensitive coating of the composition is soluble in aqueous alkaline solutions as well as in organic aprotic polar solvents, and both solvents can be used as developers. However, the resolution of patterns is quite different, especially in thick films. Solvent developers results in poor resolution, whereas aqueous alkaline developers give patterns of high aspect ratio even in thick films. This is probably due to the difference in the diffusion efficiency and swelling properties of the polymer compared to the developers.