Abstract Biobased photosensitive polyimides (PSPIs) that simultaneously exhibit low dielectric properties, high thermal stability, and reliable photolithographic performance are highly desirable for advanced microelectronic and packaging applications. In this study, a negative-type PSPI system is developed using an isosorbide-derived diamine and aromatic dianhydrides to form biobased poly(ether imides). Photosensitivity is introduced by incorporating a photobase generator into the corresponding poly(amic acid) precursor, enabling alkaline development through base-catalyzed imidization upon i -line (365 nm) exposure. Poly(ether imides) are expected to be stable during base development in photopatterning and lithography. As a result of the incorporation of alicyclic isosorbide units and ether linkages, the poly(ether imides) show low dielectric constants ( < 3.0) and dissipation factors ( < 0.01) in the GHz frequency range, satisfying typical requirements for high-frequency microelectronic applications. Among the investigated systems, the biobased poly(ether imides) exhibit distinct trade-offs in terms of optical transparency, dielectric performance, and alkaline resistance. Lithographic evaluation reveals that the optimized biobased PSPI system enables stable negative-type patterning with well-defined line-and-space features in the tens of µ m range while maintaining film thicknesses exceeding 1 µ m. These results demonstrate that the biobased poly(ether imide) system offers a promising molecular design strategy for sustainable, low-dielectric PSPI suitable for advanced microfabrication processes.
Chen et al. (Tue,) studied this question.