Patent ID: 9536834
Date: 2017-01-03
CPC Classifications: H01L

Claim:
1. A method for forming a metallization layer, comprising: depositing an under metal metallurgy (UMM) layer on a first copper barrier layer over a surface of a semiconductor substrate; forming a patterned photoresist layer above the UMM layer having one or more cavities extending from a top to a bottom of the patterned photoresist layer; forming a single metal layer from the UMM layer within the one or more cavities; patterning the UMM layer after forming the single metal layer to form a plurality of first metal layer structures; forming a nitride based diffusion barrier layer comprising a different material than the first copper barrier layer, wherein the nitride based diffusion barrier layer conforms to top and side surfaces of the plurality of first metal layer structures, continuously extends between adjacent ones of the plurality of first metal layer structures, and has a top surface aligned with top surfaces of the plurality of first metal layer structures; forming an inter-level dielectric material onto the surface of the semiconductor substrate to fill areas between the plurality of first metal layer structures, wherein the inter-level dielectric material has a top surface aligned with the top surface of the nitride based diffusion barrier layer; and forming a plurality of second metal layer structures on a second copper barrier layer arranged on the plurality of first metal layer structures, so that the plurality of first metal layer structures are separated from the plurality of second metal layer structures by the second copper barrier layer.