US Patent 8629560 Self aligned air-gap in interconnect structures

An integrated circuit structure comprising an air gap and methods for forming the same are provided. The integrated circuit structure includes a conductive line; a self-aligned dielectric layer on a sidewall of the conductive line; an air-gap horizontally adjoining the self-aligned dielectric layer; a low-k dielectric layer horizontally adjoining the air-gap; and a dielectric layer on the air-gap and the low-k dielectric layer.