Patent ID: 8143157
Filing Date: 2012-03-27
Classification: H01L

Abstract:
1. A method for fabricating a diffusion-barrier cap on a Cu-containing conductive element in an integrated-circuit device, comprising the steps: providing a substrate having a Cu-containing conductive element that is embedded laterally into a dielectric layer and that has an exposed surface, the dielectric layer being covered partially or completely by a mask layer; depositing a metal layer on the exposed surface of conductive element; inducing diffusion of metal from the metal layer into a top section of the conductive element; removing the remaining metal layer; letting diffused metal in the top section of the conductive element and particles of a second constituent react with each other so as to build a compound covering the conductive element, wherein the metal of the metal layer and the second constituent are chosen so that the compound forms a diffusion barrier against Cu diffusion; and further comprising: depositing the metal layer also on the mask layer, concurrently with the deposition of the metal layer on the conductive element; inducing diffusion of metal from the metal layer also into a top section of the mask layer; removing the remaining metal layer also from the mask layer; and letting diffused metal and particles of the second constituent also react with each other also in the top section of the mask layer so as to build a second compound covering the surface of the mask layer.