Patent ID: 8669182
Filing Date: 2014-03-11
Classification: H01L

Abstract:
1. A method of forming an interconnect structure comprising: forming a pad stack comprising an oxide, nitride, oxynitride or any combination thereof on an exposed upper surface of a dielectric material having a dielectric constant of about 3.0 or less; forming at least one opening through said pad stack and into at least a portion of said dielectric material; forming a diffusion barrier within said at least one opening and on an exposed horizontal surface of remaining portions of the pad stack; forming a conductive material on said diffusion barrier; removing a first portion of the diffusion barrier, a first portion of the conductive material and said remaining portions of the pad stack present on said dielectric material and outside said at least one opening by planarization, while maintaining a second portion of said diffusion barrier and a second portion of said conductive material in said at least one opening of said dielectric material, wherein after said planarization, said upper surface of said dielectric material is coplanar with an upper surface of said second portion of said conductive material; forming a noble metal cap directly on said upper surface of said second portion of said conductive material, said noble metal cap does not substantially extend onto an upper surface of said dielectric material that is adjacent to said second portion of said conductive material, said noble metal cap forming does not result in noble metal residues on the upper surface of said dielectric material, and said forming includes a chemical deposition process that is performed at a temperature of about 300° C. or less.