Semiconductor device and method for fabricating the same

A semiconductor device, comprising:

• a substrate;
• a first interlayer dielectric film on the substrate;
• first and second wires extending respectively in a first direction within the first interlayer dielectric film, the first and second wires being adjacent to each other in a second direction different from the first direction;
• a first recess within the first interlayer dielectric film between the first and second wires, the first recess including a sidewall defined by the first and second wires;
• a first hard mask pattern on the first interlayer dielectric film, the first hard mask pattern including a first opening overlapping with a portion of the first recess, with a portion of the first wire, and with a portion of the second wire;
• and
• an air gap within the first recess, the first hard mask pattern overhanging a portion of the air gap, while exposing portions of tops of the first and second wires,
• wherein a width of the first recess in the first direction is greater than a width of the first opening in the first direction,
• wherein the first wire includes a filling conductive film and a barrier conductive film extending along a bottom surface and a sidewall of the filling conductive film,
• wherein the first wire includes a first portion overlapping with the first opening and a second portion not overlapping with the first opening,
• wherein a height of the barrier conductive film at the first portion of the first wire is equal to or less than a height of the barrier conductive film at the second portion of the first wire, and
• wherein the barrier conductive film includes a portion protruding upward higher than an upper surface of the filling conductive film, at a location where the upper surface of the filling conductive film at the second portion of the first wire meets the barrier conductive film.

A method for fabricating a semiconductor device, the method comprising:

• forming first and second wires extending respectively in a first direction within a first interlayer dielectric film and being adjacent to each other in a second direction different from the first direction;
• forming a hard mask pattern with an opening on the first interlayer dielectric film, the opening exposing at least a portion of the interlayer dielectric film between the first wire and the second wire;
• performing a plasma treatment process on the interlayer dielectric film exposed by the opening by using the hard mask pattern as a mask;
• forming a recess within the interlayer dielectric film by removing the plasma-treated interlayer dielectric film, a width of the recess in the first direction being greater than a width of the opening in the first direction;
• and
• forming an air gap within the recess,
• wherein the hard mask pattern overhanging a portion of the air gap, while exposing portions of tops of the first and second wires.