Microelectronic structure including air gap
A microelectronic structure and a method for fabricating the microelectronic structure provide a plurality of voids interposed between a plurality of conductor layers. The plurality of voids is also located between a liner layer and an inter-level dielectric layer. The voids provide for enhanced electrical performance of the microelectronic structure.
1. A microelectronic structure comprising:
a first dielectric layer located over a substrate;
a plurality of conductor layers located embedded and planarized within the first dielectric layer and including a plurality of apertures interposed between the plurality of conductor layers;
a liner layer incompletely filling the plurality of apertures;
a second dielectric layer located upon the liner layer and enclosing a plurality of voids interposed between the liner layer and the second dielectric layer, and separating the plurality of conductor layers;
a plurality of barrier layers located upon bottom and sidewall portions of the plurality of conductor layers;
a plurality of capping layers aligned upon top surfaces of the plurality of conductor layers; and
a plurality of spacers adjoining a sidewall of the plurality of capping layers and having a thickness greater than a width of the barrier layer.
2. The structure of claim 1 wherein the plurality of voids extends within the dielectric layer deeper than the plurality of conductor layers.
3. The structure of claim 1 wherein the plurality of voids undercuts the plurality of conductor layers.
4. The structure of claim 1 wherein said first dielectric layer comprises a dielectric material having a dielectric constant of greater than 4.0.
5. The structure of claim 1 wherein said first dielectric layer comprises a dielectric material having a dielectric constant of less than 4.0.
6. The structure of claim 1 wherein said plurality of conductor layers comprise copper or a copper alloy.
7. The structure of claim 1 wherein said second dielectric layer comprises a dielectric material having a dielectric constant of greater than 4.0.
8. The structure of claim 1 wherein said second dielectric layer comprises a dielectric material having a dielectric constant of less than 4.0.
9. The structure of claim 1 wherein said a plurality of voids are enclosed by a dielectric liner material.
10. The structure of claim 9 wherein said dielectric liner material comprises silicon nitride.
11. The structure of claim 9 wherein said dielectric liner material comprises carbon doped silicon nitride.
12. The structure of claim 9 wherein said plurality of voids having an uppermost portion that extends above an uppermost surface of said dielectric liner material.