Bottom-up fill mechanisms of electroless copper plating with addition of mercapto alkyl carboxylic acid

2006; American Institute of Physics; Volume: 24; Issue: 2 Linguagem: Inglês

10.1116/1.2167988

ISSN

1520-8567

Autores

Zenglin Wang, Zhijuan Liu, Hongyan Jiang, Xiu Wei Wang,

Tópico(s)

Corrosion Behavior and Inhibition

Resumo

Copper electrodeposition is used in the damascene process for the fabrication of interconnections of ultralarge-scale integrated semiconductor devices. Copper electroless plating is one of the most promising processes for the formation of a seed layer for electroplating. In this article, the effect of additives of mercapto alkyl carboxylic acid (MACA) such as 3-mercaptopropionic acid, 11-mercaptoundecanoic acid, and 16-mercaptohexadecanoic acid on bottom-up filling of electroless copper in deep submicrometer via holes was investigated. The inhibition of copper plating deposition on the plane surface was observed with an addition of MACAs, and bottom-up fill was confirmed for MACAs with alkyl chain numbers of 3, 11, and 16. The bottom-up fill tendency was enhanced with increasing alkyl chain number. This result strongly suggests that the diffusion coefficient of inhibitor molecule plays an important role for bottom-up fill mechanisms, because MACA with longer alkyl chain has smaller diffusion coefficient than that with shorter alkyl chain.

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