Interlayer dielectrics based on copolyimides containing non-coplanar alicyclic-units for multilevel high-speed electronics

A series of copolyimides (CPIs) containing non-coplanar alicyclic units combined with fluorinated or rigid aromatic monomer segments is synthesized. The solid film samples display an elevated heat resistance as their degradation started at temperatures around 415 °C. Introduction into CPI backbone of bicyclic units, aromatic/aliphatic rings, angular bonds and/or low polarizable groups, determine the variation of the dielectric constant in the range 2.44–3.04 at 100 Hz. When using these CPIs as interlayer dielectrics (ILDs), it is revealed that resistance-capacitance delay is minimized (~10−11 s) determining faster response of the device. Atomic force microscopy scans of CPI samples show distinct macromolecular architectures, all containing nanopores with features depending on the chemical structure. Interfacial adhesion of investigated ILDs with copper wiring is highest for the samples lacking fluorine groups.