A barrier layer structure includes a first dielectric layer forming on a conductive layer and having a via being formed in the first dielectric layer, wherein the via in the first dielectric layer is connected to the conductive layer. A first metal layer is steppedly covered on the first dielectric layer. A layer of metallized materials is steppedly covered on the first metal layer, but the layer of metallized materials does not cover the first metal layer above the via bottom connected to the conductive layer in the dielectric layer. A second metal layer is steppedly covered on the layer of metallized materials, and the second metal layer is covered the first metal layer above the via bottom connected to the conductive layer in the dielectric layer. The barrier layer structure will have lower resistivity in the bottom via of the first dielectric layer and it is capable of preventing copper atoms from diffusing into the dielectric layer.