Semiconductor structure having an air-gap region and a method of manufacturing the same

1. A semiconductor structure comprising:

a first conductive material-containing layer, comprising:

a dielectric material;

at least two conductive structures in the dielectric material; and

an air-gap region in the dielectric material between the at least two conductive structures;

a first capping layer over the at least two conductive structures and the air-gap region, wherein a bottom surface of the first capping layer over the at least two conductive structures is above a bottom surface of the first capping layer over the air-gap region, and at least a portion of the first capping layer directly contacts the dielectric material;

a second capping layer between the at least two conductive structures and the first capping layer; and

a second conductive material-containing layer over the first capping layer, the second conductive material-containing layer comprising a via plug separated from the air-gap region by at least a first predetermined distance, and the via plug extends into the second capping layer.

2. The semiconductor structure of claim 1 , wherein a bottom surface of the first capping layer defines a top boundary of the air-gap region, the top boundary has a substantially flat profile.

3. The semiconductor structure of claim 1 , wherein the first predetermined distance is within a range from greater than 0.0 nm to about 50 nm.

4. The semiconductor structure of claim 1 , further comprising: a conductive pad over the second conductive material-containing layer, the conductive pad being offset from the air-gap region by at least a second predetermined distance, wherein the second predetermined distance is in a range from about 10 nm to about 20 μm.

5. The semiconductor structure of claim 1 , wherein the first capping layer has a thickness in a range from about 5.0 nm to about 50 nm.

6. The semiconductor structure of claim 1 , wherein the second capping layer is a metal capping layer.

7. The semiconductor structure of claim 6 , wherein the metal capping layer comprises cobalt tungsten phosphide (CoWP).

8. The semiconductor structure of claim 6 , wherein the first capping layer is a dielectric capping layer.

9. A semiconductor structure comprising:

a first metal-containing layer, comprising:

a dielectric material;

at least two metal structures in the dielectric material; and

an air-gap region in the dielectric material between the at least two metal structures, wherein the air-gap region directly contacts at least one of the at least two metal structures;

a first capping layer over the air-gap region, the air-gap region being limited to the first metal-containing layer by the first capping layer;

a second capping layer between the at least two metal structures and the first capping layer; and

a second metal-containing layer over the first capping layer, the second metal-containing layer comprising a via plug electrically connected to one of the at least two metal structures, the via plug being separated from the air-gap region by at least a first predetermined distance,

wherein the first capping layer comprises a first material, and the second capping layer comprising a second material different from the first material.

10. The semiconductor structure of claim 9 , further comprising a protective layer between the at least two metal structures and the air-gap region.

11. The semiconductor structure of claim 9 , wherein the first capping layer is a dielectric capping layer, and the second capping layer is a metal capping layer.

12. The semiconductor structure of claim 9 , wherein the first predetermined distance is in a first direction parallel to a top surface of the first capping layer, and the air-gap region and the conductive pad are separated by at least a second predetermined distance in the first direction.

13. A semiconductor structure comprising:

a first conductive material-containing layer, comprising:

a dielectric material;

at least two conductive structures in the dielectric material; and

at least two air-gap regions in the dielectric material, wherein one of the at least two air-gap regions is between the at least two conductive structures, and a first conductive structure one of the at least two conductive structures is between the at least two air-gap regions;

a capping layer over the at least two conductive structures and the at least two air-gap regions, wherein a bottom surface of the capping layer over a first air gap of the at least two air gaps is below a bottom surface of the capping layer over the first conductive structure;

a second conductive material-containing layer entirely over a bottom-most surface of the capping layer, wherein the second conductive material-containing layer comprising a via plug electrically separated from the air-gap region by at least a first predetermined distance; and

a conductive pad over the second conductive material-containing layer, the conductive pad being offset from the air-gap region by at least a second predetermined distance, wherein the second predetermined distance is different from the first predetermined distance.

14. The semiconductor structure of claim 13 , wherein the capping layer comprises a dielectric material.

15. The semiconductor structure of claim 13 , further comprising a metal layer between the capping layer and at least one of the at least two conductive structures.

16. The semiconductor structure of claim 13 , wherein the dielectric material is a low-k dielectric material.

17. The semiconductor structure of claim 15 , wherein the capping layer comprises a non-metal material.

18. The semiconductor structure of claim 9 , wherein a top surface of a first metal structure of the at least two metal structure is coplanar with a top surface of the air-gap region.

19. The semiconductor structure of claim 9 , wherein a portion of the first capping layer directly contacts the dielectric layer.

20. The semiconductor structure of claim 1 , wherein the dielectric material is thicker than each of the at least two conductive structures.