Abstract: A method includes forming first and second contact openings in a first dielectric layer. At least the first contact opening is at least partially lined with a liner layer. A first conductive feature is formed in the first contact opening and a second conductive feature is formed in the second contact opening. A portion of the liner layer adjacent a top surface of the first dielectric layer is removed to define a recess. A barrier layer is formed above the first dielectric layer and in the recess. The barrier layer has a first dielectric constant greater than a second dielectric constant of the first dielectric layer. A second dielectric layer is formed above the barrier layer. A third conductive feature is formed embedded in the second dielectric layer and contacting the second conductive feature.

Abstract: A method of fabricating a semiconductor device is provided. The method begins by providing a semiconductor device structure having electronic devices formed on a semiconductor substrate, and having an upper metal layer associated with electrical contacts for the electronic devices. The method continues by forming a diffusion barrier layer overlying the upper metal layer. Next, the method deposits a first layer of graded ultra-low-k (ULK) material overlying the diffusion barrier layer, a layer of ULK material overlying the first layer of graded ULK material, and a second layer of graded ULK material overlying the layer of ULK material. The method continues by depositing a layer of low temperature oxide material overlying the second layer of graded ULK material, and forming a layer of metal hard mask material overlying the layer of low temperature oxide material.