Novel photosensitive polymer based on polycarbodiimide and photoamine generator

A novel photosensitive polymer based on end-capped polycarbodiimide (E-PCD) and the photoamine generator N-{[(4,5-dimethoxy-2-nitrobenzyl)oxy]carbonyl }-2,6-dimethylpiperidine (1) was developed. The E-PCD was prepared by polyc ondensation of tolylene-2,4-diisocyanate in the presence of 3-methy-1-pheny l-2-phospholene-1-oxide as a catalyst. The reaction of carbodiimide and sec ondary amine was studied. The nucleophilic addition of amine to the carbodi imide moiety proceeded smoothly and provided a guanidine base that acted as a crosslinking agent. A lithographic evaluation of the system of E-PCD and 1 revealed that the dissolution rate of the exposed area after the postexp osure bake decreased drastically, although no obvious change of the dissolu tion rate in the unexposed area was observed. The E-PCD containing 10 wt % 1 functioned as a negative working photosensitive polymer when it was expos ed to 365-nm UV light, postbaked at 120 degrees C for 5 min, and developed with toluene at 25 degrees C. (C) 2000 John Wiley & Sons, Inc.