Building reliability into a high performance 4-level metallization system

Building reliability into MLM systems implies an a priori understanding of the mechanisms leading to failure for a given metallization technology. We present one approach to 'building-in reliability', by developing a database of electro- and stress-migration, and microstructural data for several Al-Cu(1.5%):Ti-W metallurgies. By performing experiments that exceed the targets for a given technology, the key process and design parameters impacting reliability for subsequent technologies were identified. In this paper we present experimental results obtained developing this database. We also show the development of a simple predictive model, for lines and vias, based on the key process and design parameters. Our results highlight one approach used to develop a building-in reliability capability for complex MLM interconnect systems.<
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