Design and reliability aspects of multilevel metal large-scale power line layouts in ULSI-ICs

Integration of both extremely small-dimensioned metal lines and large-dimensioned metal structures may cause reliability problems due to thermomechanical stress between the intermetal dielectric and the multi-level-metalization. The paper reports a case study and shows a problem solution approach: due to thermomechanical mismatch of aluminum and Si-oxide, metalization processing should not be used for both small and large structures. This may cause cracks and generate intermetallic shorts as a reliability problem.