Interconnect structure and methods of forming the same

An interconnect structure, comprising

• a dielectric layer;
• a first conductive feature disposed in the dielectric layer;
• a conductive layer disposed over the dielectric layer, wherein the conductive layer includes a first portion and a second portion adjacent the first portion, and the second portion of the conductive layer is disposed over the first conductive feature;
• a first barrier layer in contact with the first portion of the conductive layer;
• a second barrier layer in contact with the second portion of the conductive layer, wherein the first and second barrier layers are separated by an air gap;
• and
• a capping layer in contact with the first barrier layer, the second barrier layer, and the dielectric layer, wherein a portion of the capping layer is exposed to the air gap.

A method for forming an interconnect structure, comprising:

• forming a conductive layer over a dielectric layer;
• forming one or more openings in the conductive layer to expose portions of the dielectric layer, wherein the one or more openings separates the conductive layer into one or more portions;
• forming a blocking layer on an exposed surface of the dielectric layer;
• forming barrier layers in contact with the portions of the conductive layer;
• forming a capping layer on the barrier layers;
• forming a dielectric material on the capping layer to fill the one or more openings;
• and
• performing a planarization process until the portions of the conductive layer are exposed.