SYNTHESIS OF A PHOTOSENSITIVE POLY(ARYLENE ETHER) CONTAINING PENDANT BENZOYL GROUPS

Poly(arylene ether) (3) containing 4-isopropylbenzoyl groups was prepa red by a nucleophilic substitution reaction of 1,4-bis(4-isopropylbenz oyl)-2,5-difluorobenzene (1) with methylhydroquinone (2) in the presen ce of potassium carbonate in N,N-dimethylacetamide. The polycondensati on proceeded smoothly at 165 degrees C and produced a poly(arylene eth er) with an inherent viscosity of 0.93 dL/g. The polymer was quite sol uble in common organic solvents and could be processed into uniform fi lms from solution. Thermogravimetry of the polymer showed a 10% weight loss at 430 degrees C in a nitrogen atmosphere. The glass transition temperature of polymer was 140 degrees C. The polymer functioned as a positive photoresist for UV irradiation. The resist had a sensitivity of 300 mJ/cm(2) and a contrast of 0.67 when it was postbaked at 150 de grees C for 15 minutes followed by development with toluene/2-propanol at room temperature.