NOVEL PHOTOSENSITIVE POLYIMIDE PRECURSOR BASED ON POLYISOIMIDE USING AN AMINE PHOTOGENERATOR

摘要

A new amine photogenerator N-{[(4,5-dimethoxy-2-nitrobenzyl)oxy]carbonyl}-2,6-dimethylpiperidine (3) was prepared from 2,6-dimethylpiperidine and 4,5-dimethoxy-2-nitrobenzyl p-nitrophenylcarbonate, Compound 3 has a long wavelength band with an absorption maximum at 350 nm and the absorption tail extending out to 400 nm. 3 was found to be effective for the isomerization of polyisoimide (PII) to the corresponding polyimide (PI). The Pn was prepared by the ring-opening polyaddition of oxydiphthalic anhydride (ODPA) and 3,3'-diaminodiphenyl sulfone (3,3'-DDS), followed by treatment with trifluoroacetic anhydride-triethylamine (TEA) in N-methyl-2-pyrrolidone (NMP). The PII film showed excellent. UV transparency above 300 nm and a wide range of solubility in organic solvents. The isomerization behavior of the PII film containing 3-30 wt % of 3 after exposure and postexposure bake (FEB) has been studied and it was found that the isomerization ratio in the exposed area was 15-75%, while no obvious isomerization at the same FEB temperature was observed in the unexposed area. The PII containing 10 wt Q of 3 functioned as a photosensitive resist, when it was postbaked at 150 degrees C for 5 min followed by development with cyclohexanone at 45 degrees C. [References: 20]