Patent ID: 8476758
Filing Date: 2013-07-02
Classification: H01L

Abstract:
1. A method of fabricating an interconnect structure comprising: providing a blanket layer of a photo-patternable low-k material on a surface of an inorganic antireflective coating (ARC), said inorganic ARC is located atop a substrate and comprises atoms of M, C and H wherein M is at least one of Si, Ge, B, Sn, Fe, Ta, Ti, Ni, Hf and La; forming at least one interconnect pattern within said blanket layer of the photo-patternable low-k material, said at least one interconnect pattern is formed without utilizing a separate photoresist and with an uppermost surface of the photo-patternable low-k material being entirely bare; curing said photo-patternable low-k material containing said at least one interconnect pattern into a dielectric material containing said at least one interconnect pattern and having a dielectric constant of not more than 4.3; etching an exposed portion of said inorganic ARC to form an opening in said inorganic ARC, wherein said opening extends from an uppermost surface of the exposed portion of said inorganic ARC to a bottommost surface of said inorganic ARC and exposes an upper surface portion of said substrate, and wherein said opening within said inorganic ARC is at least vertically coincident to a lower portion of the at least one interconnect pattern; filling said at least one interconnect pattern in said dielectric material and said opening within said inorganic ARC with a conductive material; forming a stack comprising a dielectric cap and a block mask located atop said dielectric material that contains the at least one interconnect filled with said conductive material; forming at least one airgap through said stack and into said dielectric material, wherein wall portions of the at least one airgap are in contact with said dielectric material, and wherein said forming the at least one airgap comprises forming at least one airgap opening through said stack and into said dielectric material by etching, removing the block mask from atop said dielectric cap, changing portions of the dielectric material that are directly abutting said at least one airgap opening by chemical treatment, while other portions remain unchanged, and isotropic etching said changed portions relative to said unchanged portions; and forming an airgap cap atop said dielectric cap, wherein said airgap cap does not extend below an uppermost surface of said dielectric cap and wherein said airgap does not extend into said airgap cap.