A metal interconnection structure includes a lower metal interconnection layer
disposed in a first inter-layer dielectric layer. An inter-metal dielectric layer
having a via contact hole that exposes a portion of surface of the lower metal
layer pattern is disposed on the first inter-layer dielectric layer and the lower
metal layer pattern. A second inter-layer dielectric layer having a trench that
exposes the via contact hole is formed on the inter-metal dielectric layer. A barrier
metal layer is formed on a vertical surface of the via contact and the exposed
surface of the second lower metal interconnection layer pattern. A first upper
metal interconnection layer pattern is disposed on the barrier metal layer, thereby
filling the via contact hole and a portion of the trench. A void diffusion barrier
layer is disposed on the first metal interconnection layer pattern and a second
upper metal interconnection layer pattern is disposed on the void diffusion barrier
layer to completely fill the trench.