Integrated Circuit Interconnect Structures with Air Gaps

A method comprising:

• receiving a substrate and an interconnect structure disposed on the substrate, wherein the interconnect structure includes:
• an interconnect dielectric layer;
• and
• a plurality of conductive features disposed in the interconnect dielectric layer;
• forming an etch stop layer on the interconnect structure, wherein the forming of the etch stop layer includes:
• selectively forming an etch stop conductor on the plurality of conductive features;
• and
• selectively forming an etch stop dielectric on the interconnect dielectric layer;
• and
• forming a gap between the plurality of conductive features.

A device comprising:

• a substrate;
• an inter-level dielectric layer disposed on the substrate;
• a plurality of conductive features disposed within the inter-level dielectric layer;
• an etch stop layer disposed on the inter-level dielectric layer and on the plurality of conductive features;
• and
• a gap extending between two of the plurality of conductive features.