Self-forming barrier for use in air gap formation

A method of forming a semiconductor device, comprising:

• providing parallel interconnects disposed in a dielectric material, wherein each of the parallel interconnects comprises:
• a manganese doped copper interconnect material disposed in a liner;
• and
• a conductive cap disposed on the manganese doped copper interconnect material;
• depositing one or more additional layers on the dielectric material and exposed surfaces of the conductive caps;
• subsequent to depositing the one or more additional layers, applying a thermal treatment to the parallel interconnects, wherein the thermal treatment forms a layer comprising:
• manganese between the liner and the dielectric material;
• and
• manganese between the conductive cap and the one or more additional layers;
• patterning a lithography stack to form:
• a first region where a first portion of the dielectric material is exposed;
• and
• a second region where a second portion of the dielectric material is covered;
• damaging the first portion of the dielectric material in the first region by exposing the first portion of the dielectric material to a chemical or plasma attack;
• and
• etching the damaged first portion of the dielectric material between the parallel interconnects in the first region via a wet etch process to define air gaps.