Joint university and industry investigation of polyimide for thin film organic dielectrics for VLSI interlevel applications

An investigation of acetylene functional polyimide oligomers has demonstrated some of the advantages connected with their use as the starting materials for an interlayer dielectric film in the fabrication of IC devices. Results are presented on two acetylene functional, fully imidized polyimide oligomers. One oligomer is an isoimide structure which can be deposited to form a thin film by spin coating from solvent at high solids levels. The second oligomer is a fully normal imidized structure which contains fluorine atoms and hence shows excellent solubility before cure and generates a low dielectric constant film after cure. The use of these polyimide oligomers as ion implant masks for boron and phosphorus was also demonstrated