Patent ID: 7538353

Claim:
A dual damascene structure comprising: a substrate; a composite barrier/etch stop layer formed over the substrate, the composite barrier/etch stop layer comprising a lower silicon carbide (SiC) layer and an upper first oxygen doped SiC layer wherein the upper first oxygen doped SiC layer has a silicon content from about 25 to 35 atomic weight %, a carbon content of about 17 to 25 atomic wt. %, an oxygen content of about 5 to 15 atomic wt. %, and a hydrogen content from about 20 to 40 atomic wt. %; a first dielectric layer formed over the upper first oxygen doped SiC layer; a second oxygen doped SiC etch stop layer formed over the first dielectric layer wherein the second oxygen doped SiC etch stop layer has a silicon content from about 25 to 35 atomic weight %, a carbon content of about 17 to 25 atomic wt. %, an oxygen content of about 5 to 15 atomic wt. %, and a hydrogen content from about 20 to 40 atomic wt. %; a second dielectric layer formed over the second oxygen doped SiC layer; an opening having sidewalls and a bottom, the opening extending through the second dielectric layer, the second oxygen doped SiC etch stop layer, the first dielectric layer, the upper first oxygen doped SiC layer and at least a portion of the lower silicon carbide SiC layer, the opening comprising a via and a trench located in the second dielectric layer aligned above sad via; and a conformal diffusion barrier lining the sidewalls and the bottom of said opening and a metal layer formed on the diffusion barrier layer, the metal layer filling the opening.