Method of manufacturing an enhanced electromigration performance hetero-junction bipolar transistor

1. A method comprising:

forming at least one metal line in electrical contact with a device; and

forming at least one staple structure in electrical contact with the at least one metal line, the at least one staple structure is formed such that electrical current passing through the at least one metal line also passes through the at least staple structure to reduce electromigration issues; wherein forming of the at least one staple structure comprises:

forming, in a dielectric material, a plurality of vias and a trench spanning between the plurality of vias;

lining the plurality of vias and the trench with a conductive liner; and

filling the plurality of vias and the trench with a conductive material such that the filling of the trench forms a conductive bar in direct electrical contact with the conductive material in the vias.

2. The method of claim 1 , wherein the at least one metal line is formed as a last metal line in electrical contact with a bipolar transistor and the at least one staple structure provides a blocking zone.

3. The method of claim 1 , wherein the plurality of vias is two vias in direct electrical contact with the at least one metal line and which are spaced apart less than a Blech length.

4. The method of claim 1 , wherein:

the at least one metal line is a plurality of metal lines;

the plurality of vias is more than two vias formed in direct electrical contact with at least two of the plurality of metal lines; and

the conductive bar is formed in direct electrical contact with the more than two vias filled with the conductive material.

5. The method of claim 1 , wherein the plurality of vias is more than two vias filled with the conductive material and formed in direct electrical contact with the at least one metal line, and the conductive bar is formed in direct electrical contact with the more than two of the vias.

6. The method of claim 1 , wherein the at least one metal line is formed as two or more metal lines and the at least one staple structure is formed in direct electrical contact with at least two of the two or more metal lines.

7. The method of claim 1 , wherein the plurality of vias and the trench are lined with tantalum, nitride or ruthenium, and then filled with copper material to form the at least one staple structure.

8. The method of claim 7 , further comprising capping the filled trench with SiN.

9. The method of claim 1 , wherein the forming of the at least one staple structure comprises:

forming a plurality of staggered staple structures in the dielectric material, in direct electrical contact with the at least one metal line, wherein the forming of the plurality of staggered staple structures comprises:

forming a plurality of vias in the dielectric material;

forming a plurality of trenches in the dielectric material, each of which are in contact with at least two of the plurality of vias;

lining the plurality of vias and trenches with a conductive liner;

filling the plurality of vias and trenches with a conductive material over the conductive liner; and

capping the trenches with a capping material.

10. The method of claim 9 , wherein:

the conductive liner is tantalum, nitride or ruthenium;

the conductive material is copper; and

the capping material is SiN.

11. The method of claim 1 , wherein the at least one metal line is formed as three or more metal lines and the at least one staple structure is formed in direct electrical contact with at least two of the three or more metal lines.

12. A method of forming a structure, comprising:

forming a last wiring layer in a dielectric layer, in electrical contact with a transistor formed in a lower layer of the structure;

forming at least one via hole in the dielectric layer, exposing the last wiring layer;

forming at least one trench in the dielectric layer and over the at least one via hole;

lining the at least one via hole and the at least one trench with conductive liner material;

filling the at least one via hole and the at least one trench with conductive material such that the at least one via hole forms at least one conductive via and the at least one trench forms a conductive bar structure in direct electrical contact with the at least one conductive via, and electrical current flowing in the last wiring layer can also flow through the at least one conductive via and the conductive bar structure to mitigate electromigration effects in the last wiring layer; and

forming a liner on the filled at least one via hole and the at least one trench and extending onto a surface of the dielectric layer,

wherein the conductive bar structure and the at least one conductive via are formed to span at least two wiring layers.

13. The method of claim 12 , wherein the at least one via hole and the at least one trench are formed in a dual damascene process.

14. The method of claim 12 , wherein the conductive bar structure is formed in direct electrical contact with at least two of the conductive vias.

15. The method of claim 12 , wherein the conductive liner material is tantalum, nitride or ruthenium, and the conductive material is copper.

16. The method of claim 12 , wherein the conductive bar structure and the at least one conductive via form a staple structure.

17. The method of claim 12 , wherein the conductive bar structure and the at least one conductive via form a “T” structure.

18. The method of claim 1 , wherein:

the forming at least one metal line comprising forming two metal lines;

the plurality of vias forming the at least one staple structure comprises forming a first via directly on a first metal line of the two metal lines and a second via directly on a second metal line of the two metal lines;

the trench connects the first via to the second via, thereby straddling between the two metal lines; and

the first via, the second via and the trench are lined with the conductive liner, prior to the forming of the conductive material thereon.

19. The method of claim 1 , wherein:

the plurality of vias forming the at least one staple structure comprises forming a first via directly on a first metal line and a second via directly on the first metal line of the at least one metal line;

the trench connects the first via to the second via, thereby straddling over the first metal line; and

the first via, the second via and the trench are lined with the conductive liner, prior to the forming of the conductive material thereon.