CuSiN/SiN DIFFUSION BARRIER FOR COPPER IN INTEGRATED-CIRCUIT DEVICES

摘要

The present invention relates to an integrated-circuit device that has at least one Copper-containing feature in a dielectric layer, and a diffusion-barrier layer stack arranged between the feature and the dielectric layer. The integrated-circuit device of the invention has a diffusion-barrier layer stack, which comprises, in a direction from the Copper-containing feature to the dielectric layer, a CuSiN layer and a SiN layer. This layer combinat ion provides an efficient barrier for suppressing Copper diffusion from the feature into the dielectric layer. Furthermore, a CuSiN/SiN layer sequence provides an improved adhesion between the layers of the diffusion-barrier layer stack and the dielectric layer, and thus improves the electromigration performance of the integrated-circuit device during operation. Therefore, the reliability of device operation and the lifetime of the integrate- circuit device are improved in comparison with prior-art devices. The invention further relates to a method for fabricating such an integrated-circuit device.