Patent ID: 8877601

Claim:
A method for forming a semiconductor structure, comprising: forming an active device region in and on a semiconductor substrate; forming an interconnect layer over the active device region, wherein the interconnect layer comprises a first dielectric material having a first dielectric constant, a first metal interconnect in the first dielectric material, and a second metal interconnect in the first dielectric material and laterally spaced apart from the first metal interconnect; removing a portion of the first dielectric material such that a remaining portion of the first dielectric material remains within the interconnect layer, wherein the removed portion is removed from a location between the first and second metal interconnects; and filling the location between the first and second metal interconnects from which the portion of the first dielectric material was removed with a second dielectric material having a second dielectric constant, the second dielectric constant being higher than the first dielectric constant, wherein the step of filling comprises: depositing a layer of the second dielectric material over the interconnect layer; and removing portions of the layer of the second dielectric material which extend above the interconnect layer such that a remaining portion of the layer of the second dielectric material remains over each of the first and second metal interconnects; and forming a second interconnect layer over the remaining portion of the layer of the second dielectric material, wherein the remaining portion of the layer of the second dielectric material is between the second interconnect layer and each of the first and second metal interconnects.