A Review of the Limitations of Aluminum Thin Films on Semiconductor Devices

This paper reviews several time dependent reliability limitations of aluminum thin film metallization used on semiconductor devices., For each of the degradation modes, the present level of understanding as well as engineerlng data are presented. First, interactions of aluminum with the underlying silicon substrate, with silicon dioxide, and with gold are discussed. Then the time dependent degradation phenomena of electromigration, surface reconstruction, and corrosion are reviewed. A good understanding of all these limitations is important in the construction of reliable devices using this metallization.