Infineon Technologies Ag

Gregoire Grandremy

Matthias Lehr

Gabriela Brase

The novel etching process for a two-layer metallization, or dual damascene patterning, is simple and cost-effective to carry out and reliably prevents fences from forming during the etching process in the region of the polymer intermediate layer. The etching of the oxide layer and of the polymer intermediate layer for the dual damascene patterning is effected by a CFARC open process with high selectivity with respect to the photoresist with a lengthened etching time.

Etching process for a two-layer metallization

An antireflection coating (ARC) polymer layer is patterned by DUV (deep ultraviolet) lithography followed by an ARC open etching step and subsequent etching of the metal layer. Low resist consumption and hence steeper resist sidewalls are achieved by virtue of the ARC polymer intermediate layer being etched with a CF ARC open process with high selectivity with respect to the photoresist. The gas flows are set to the following ranges: CF 35-45 sccm, CHF 17-23 sccm, O 5-7 sccm and Ar 80-120 sccm.

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Dresden, Germany

Gregoire Grandremy