Reliability study of planarized aluminum metallization

This work investigates the reliability issues associated with an aluminum process, called the Al-plug process, that results in the complete filling of submicron contacts and vias. It has been demonstrated that the Al-plug process is a viable means of filling high aspect ratio vias and contacts for submicron geometries and can be used without degrading device reliability. It also has been experimentally determined that the film's microstructural parameters such as surface roughness, grain size, Si nodules and hillock formation are improved over the conventionally deposited Al-Si-Cu film. Both electromigration and stress-induced migration data also indicate that the Al-plug metal film is highly reliable. The planarity of the Al-Si-Cu lines in vias and over steps is excellent compared to that of a standard metal process.<
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