Patent ID: 7427563

Claim:
A method for forming a copper interconnect having a dielectric copper barrier layer, the method comprising: providing a substrate having formed thereon copper interconnect structures and an insulating layer that overlies the copper interconnect structures, the insulating layer having an opening that exposes an underlying copper interconnect structure and is configured to receive an inlaid conducting structure that is in electrical contact with the copper interconnect structure, the insulating layer being formed of a low-K dielectric material that includes at least one of silicon and carbon material; treating the insulating layer so that a dielectric copper barrier layer is formed on the inside surface of the opening thereby producing a barrier to copper diffusion into the insulating layer, wherein treating the insulating layer includes selectively forming a silane precursor layer on the substrate such that it is not formed on the exposed underlying copper interconnect structure and then reacting the silane precursor layer to form a silicon carbide sub-layer of copper barrier material having a thickness in the range of about 2-5 Åand wherein the process is repeated to form additional silicon carbide sub-layers until a final dielectric copper barrier layer is formed having a desired thickness; and filling the opening with a copper material.