Soluble and optically transparent fluorine‐containing photoreactive polyimide precursors: Spectral sensitization by organic peroxide and organic dye combination

Photoreactive polyimide precursors involving the hexafluoropropyl group with chain structure have been developed. These polyimide precursors are readily soluble in common organic solvents and optically transparent for light of 365nm wave length (i‐line) similar to aliphatic polyimide precursors. These precursors offer high resolution patterns with aspect ratio of more than 2.0. In these polyimide precursors, the polymers which have a benzophenone segment in the polymer backbone are self‐sensitized, and show interesting photochemical reactions. The authors have been also tried to extend the range of spectral sensitivity of BPDA‐AMHFP toward longer wavelengths (> 436 nm) by the addition of an organic peroxide (BTTB) and a sensitizing dye selected from coumarine, ketocoumarine, xanthen, etc.