Photopatternable Highk Fluoropolymer Dielectrics Bearing Pendent Azido Groups

Photopatternable fluoropolymers with high dielectric constant were prepared by direct azidation of commercially available poly(vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene). The produced fluoropolymers exhibit very high dielectric constant, while being photopatternable without the use of any additives. These cross-linked polymers appear to have reduced crystallinity compared to the pristine ones, as cross-linking is known to introduce defects in the polymer conformation, leading to a reduction in crystallinity. Cross-linking can occur both thermally and photochemically because of the presence of the pendent azido groups, which upon heating or irradiation with UV light release nitrogen and act as cross-linking sites. The cross-linked films exhibit excellent dielectric properties which greatly depend on the reaction conditions. Appropriate photolithographic protocols have been developed to obtain excellent quality patterned films using the azide-containing fluoropolymer as negative photoresist.

K. KALLITSIS, D. THUAU, T. SOULESTIN, C. BROCHON, E. CLOUTET, F. DOMINGUES DOS SANTOS, G. HADZIIOANNOU

ACS Macromolecules, 52, 15, 5769-5776, https://pubs.acs.org/doi/abs/10.1021/acs.macromol.9b00508 2019