Advanced barrier systems for copper metallization in high integrated circuits

摘要

Performance and reliability of microelectronic devices is significantly determined by the interconnect technology. Particularly manufacturer of microprocessors have worked intensively on copper wiring technology. The stability of the diffusion barrier which has to avoid the diffusion of copper into interlayer dielectrics and into active transistor regions is a crucial factor for the reliability of copper interconnects. Barrier thickness of less than 20 nm, as shown in the SIA roadmap for the next technology nodes, are a big challenge to barrier material as well as process technology. Tantalum based diffusion barriers are described, and an outlook to future R&D is given.