Patent ID: 7179760

Claim:
An interconnect structure, comprising: a conductor embedded in an interlevel dielectric (ILD) material with a conductive diffusion barrier liner therebetween, wherein top surfaces of the conductor, the ILD material, and the conductive diffusion barrier liner comprise micro-steps therebetween; and a bilayer cap structure comprising: a first cap layer overlaying the conductor, the ILD material, and the conductive diffusion barrier liner, wherein said first cap layer is formed by an unbiased high density plasma (HDP) chemical vapor deposition process and has a columnar growth pattern with seams located along the micro-steps between the top surfaces of the conductor, the ILD material, and the conductive diffusion barrier liner; and a second cap layer overlaying the first cap layer, wherein said second cap layer is formed by a biased high density plasma (bHDP) chemical vapor deposition process and has a seamless, isotropic growth pattern.