Synthesis of Polyhydroxyimides for Negative-Tone Photosensitive Polyimides with Enhanced Patterning Stability

To mitigate the significant film shrinkage typically observed in conventional poly(amic acid) (PAA)-based photosensitive polyimides (PSPIs), we developed cross-linked, chemically amplified photosensitive polyhydroxyimides (PSPHIs). Polyhydroxyimides (PHIs) synthesized from three structurally distinct dianhydrides exhibited tunable thermal and optical properties, enabling controlled cross-linking and negative-tone behavior. The resulting PSPHI films demonstrated excellent dimensional stability during the development process, achieving high pattern retention ratios of 87–94%. These findings demonstrate that the proposed PSPHI systems effectively suppress film shrinkage and enhance pattern fidelity, offering strong potential for use as next-generation polymeric materials in microelectronic packaging applications.