Photosensitive Polynorbornene as a Dielectric Material for Packaging Applications

摘要

The rapid development of microelectronic industry creates high demand for low dielectric constant (low-k) materials. Polynorbornene (Avatrel~(TM)) is a new photodefinitable dielectric material developed by B. F. Goodrich Company. A type of cationic photoinitiator, onium salts, is used to initiate the crosslinking reaction of epoxide groups. The reaction mechanism of poly[decylnorbornene-co-epoxidenorbomene] was studied. The structure/property relations of polymer film were investigated. Copolymer compositions and process conditions affect the properties of the polymer film. A lower content of epoxidenorbornene results in lower dielectric constant, lower residual stress, better adhesion, and good photodefinition, but poor multilayer capability. Lower exposure dose, lower post bake temperature and shorter post bake time improve photodefinition.