Barrier layer for a copper metallization layer including a low k dielectric

摘要

The effect of resist poisoning may be eliminated or at least substantially reduced in the formation of a low-k metallization layer, in that a nitrogen-containing barrier/etch stop layer is provided with a significantly reduced nitrogen concentration at an interface in contact with said low-k dielectric material. Consequently, diffusion of nitrogen and nitrogen compounds in vias formed in said low-k dielectric layer is significantly suppressed, so that in a subsequent photolithographic step, interaction of nitrogen and nitrogen compounds with the photoresist is remarkably reduced.