Patent ID: 8754526

Claim:
An interconnect structure comprising: a lower interconnect level comprising a first dielectric material having a first conductive material embedded therein; an upper interconnect level comprising a second dielectric material of unitary composition and having at least one opening that is in contact with said first conductive material of the lower interconnect level, wherein said second dielectric material of unitary composition has a second conductive material embedded within said at least one opening that is laterally spaced apart from said second dielectric material of unitary composition by a diffusion barrier and a dense dielectric spacer, said diffusion barrier having a first vertical sidewall surface and a second vertical sidewall surface, said first vertical sidewall of said diffusion barrier is in contact with at least said second conductive material, and wherein said second vertical sidewall surface of said diffusion barrier has a first portion in directly physical contact with a sidewall surface of said dense dielectric spacer and a second portion in direct physical contact with a sidewall surface of said second dielectric material of unitary composition; and an air gap located between said dense dielectric spacer and an upper portion of said second dielectric material of unitary composition.