Semiconductor device having multi-layer copper line and method of forming the same

Abstract

A semiconductor device includes a lower copper line formed on a substrate, an interlayer insulating layer formed on the lower copper line, and an upper copper line formed on the interlayer insulating layer. A copper via contact extends through the interlayer insulating layer for electrically connecting the lower copper line and the upper copper line. A concave recess is formed within the lower copper line and is vertically aligned and arranged below the copper via contact. A patterned barrier layer is formed at a bottom portion of the concave recess, such that the lower copper line and the copper via contact are directly electrically connected at an interface along sides of the concave recess, without an intervening barrier layer.

Dependencies are inferred from the claim text.