Chemical-Mechanical Polishing for Fabricating Patterned Tungsten Metal Features as Chip Interconnects

Interconnect features of tungsten metal, recessed in an SiO sub 2 dielectric, can be formed using a novel chemical-mechanical polish process. Mechanical action, to continually disrupt a surface passivating film on W, and chemical action, to remove W, appear to be requirements for workability of the...

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Bibliographic Details
Published in:Journal of the Electrochemical Society 1991-11, Vol.138 (11), p.3460-3465
Main Authors: Kaufman, F B, Jaso, M A, Pearson, D J, Small, M B, Thompson, D B, Broadie, R E, Guthrie, W L
Format: Article
Language:English
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Summary:Interconnect features of tungsten metal, recessed in an SiO sub 2 dielectric, can be formed using a novel chemical-mechanical polish process. Mechanical action, to continually disrupt a surface passivating film on W, and chemical action, to remove W, appear to be requirements for workability of the process. A trial process chemistry using a ferricyanide etchant is described. Removal of the W is discussed in terms of competition between an etching reaction which dissolves W and a passivation reaction to reform WO sub 3 on the surface of the W. This novel processing technology is compared with earlier methods of fabricating metal interconnect structures.
ISSN:0013-4651