Preparation of Novel Photosensitive Polyimide Systems via Long-Lived Active Intermediates

Polyimides are widely used in microelectronics field as passivation coatings, alpha-particle barriers, and interlayer dielectrics due to their planarization and insulating ability, as well as their good thermal and mechanical properties. Recently increasing researches have been devoted for developing photosensitive polyimides because they can eliminate a number of processing steps required for patterning usual polyimide films by using usual photoresist materials. In addition, they are expected to play a great role in manufacturing photonics devices as optical memory matrices, wave-guide materials, and non-linear optical materials in near future, when higher thermal stability and better processability would be required for designing and controlling the hyperfine structures in such materials. Several types of photosensitive polyimides have been proposed, but each system has some problems still unresolved. For example, fine patterns in polyimide precursor systems are subject to distortion due to the shrinking during imidization after exposure and development because they contain fairly