Inter-layer interconnection structure for large electrical connections

1. A method for forming an electrical interconnection structure for connection to large electrical contacts, the method comprising:

providing a semiconductor substrate having a copper-containing pad layer formed thereon such that the copper-containing pad layer includes a plurality of elongate slots having a long axis, a short axis, and sidewalls, the slots extending through the pad layer to expose the underlying semiconductor substrate;

forming, over the pad layer, a dielectric layer having a plurality of elongate openings formed therein, the elongate openings having a long axis, a short axis, and sidewalls and are configured to extend into the dielectric layer to a depth sufficient to expose the sidewalls of the slots in the copper-containing pad layer all the way down to the underlying semiconductor substrate, thereby enabling electrical connections to the underlying copper-containing pad layer; and

forming elongate copper-containing contacts in the plurality of elongate openings, said contacts physically contacting the exposed portions of the sidewalls thereby establishing electrical connections to the underlying copper-containing pad layer.

2. A method as in claim 1 wherein the step of forming the dielectric layer comprises forming the dielectric layer such that the long axis of the elongate slots lies substantially parallel to the long axis of the elongate trenches in the pad layer to expose a portion of the sidewalls of the elongate trenches of the pad layer.

3. A method as in claim 2 wherein the step of forming elongate copper-containing contacts in the plurality of elongate trenches includes the steps of:

forming at least one barrier layer in the elongate slots;

forming a seed layer in the elongate slots;

forming a bulk copper-containing layer on the seed layer; and

conducting further processing that includes removing excess copper-containing materials from a surface of the dielectric layer and electrically connecting the elongate copper-containing contacts to other circuit elements.

4. A method as in claim 3 wherein the step of conducting further processing includes forming other semiconductor circuit structures.

5. A method as in claim 1 wherein the step of forming the dielectric layer comprises forming the dielectric layer such that the long axis of the elongate openings of the dielectric layer lie transverse to the long axis of the elongate slots of the pad layer thereby exposing the substantial portions of the sidewalls of the pad layer.

6. A method as in claim 5 wherein the step of forming elongate copper-containing contacts in the plurality of elongate trenches includes the steps of:

forming at least one barrier layer in the elongate slots;

forming a seed layer in the elongate slots;

forming a bulk copper-containing layer on the seed layer; and

conducting further processing that includes removing excess copper-containing materials from a surface of the dielectric layer and electrically connecting the elongate copper-containing contacts to other circuit elements.

7. A method as in claim 6 wherein the step of conducting further processing includes forming other semiconductor circuit structures.

8. A method for forming an electrical interconnection structure for connection to large electrical contacts, the method comprising:

providing a semiconductor substrate having a conductive pad layer formed thereon such that the copper-containing pad layer includes a plurality of elongate slots having a long axis, a short axis, and sidewalls, the slots extending through the pad layer to expose the underlying semiconductor substrate;

forming a dielectric layer over the pad layer;

forming a plurality of elongate trenches in the dielectric layer, the elongate trenches having a long axis, a short axis, and sidewalls and are configured to such that the long axis of the elongate trenches lies transverse to the long axis of the elongate slots in the pad layer to expose portions of the sidewalls of the elongate slots of the pad layer to a depth that extends all the way down to the underlying semiconductor substrate and wherein the trenches extend sufficiently deep into the dielectric layer so that electrical connections to the underlying conductive pad layer can be formed; and

filling the elongate trenches of the dielectric layer with a conductive material to form conductive contacts which for electrical contacts with the exposed portions of the sidewalls and tops of the conductive pad, thereby establishing electrical connections to the underlying conductive pad layer.

9. A method as in claim 8 wherein the step of filing the plurality of elongate trenches includes the steps of:

forming at least one barrier layer in the elongate slots;

forming a seed layer in the elongate slots;

forming a bulk copper-containing layer on the seed layer; and

removing excess copper-containing materials from a surface of the dielectric layer and electrically connecting the elongate copper-containing contacts to other circuit elements.

10. A method as in claim 9 including forming electrical connections to other semiconductor circuit elements.

11. A method as in claim 9 including forming an electrically conductive top pad on the dielectric layer wherein the top pad is electrically connected with the conductive contacts.

12. A method for forming an electrical interconnection structure for connection to large electrical contacts, the method comprising:

providing a semiconductor substrate having a copper-containing pad layer formed thereon such that the copper-containing pad layer includes a plurality of elongate slots having a long axis, a short axis, and sidewalls, the slots extending through the pad layer to expose the underlying semiconductor substrate;

forming, over the pad layer, a dielectric layer having a plurality of elongate openings formed therein, the elongate openings having a long axis, a short axis, and sidewalls and are configured to extend into the dielectric layer to a depth sufficient to expose a portion of at least one of the sidewalls of the slots of the copper-containing pad layer, wherein the exposed portion extends a majority of the distance down the sidewall toward the underlying semiconductor substrate, thereby enabling electrical connections to the underlying copper-containing pad layer; and

forming elongate copper-containing contacts in the plurality of elongate openings, said contacts physically contacting the exposed portions of the sidewalls thereby establishing electrical connections to the underlying copper-containing pad layer.

13. A method for forming an electrical interconnection structure for connection to large electrical contacts, the method comprising:

providing a semiconductor substrate having a conductive pad layer formed thereon such that the copper-containing pad layer includes a plurality of elongate slots having a long axis, a short axis, and sidewalls, the slots extending through the pad layer to expose the underlying semiconductor substrate;

forming a dielectric layer over the pad layer;

forming a plurality of elongate trenches in the dielectric layer, the elongate trenches having a long axis, a short axis, and sidewalls and are configured to such that the long axis of the elongate trenches lies transverse to the long axis of the elongate slots in the pad layer to expose a portion of at least one of the sidewalls of the slots in the copper-containing pad layer, wherein the exposed portion extends a majority of the distance down the sidewall toward the underlying semiconductor substrate and wherein the trenches extend sufficiently deep into the dielectric layer so that electrical connections to the underlying conductive pad layer can be formed; and

filling the elongate trenches of the dielectric layer with a conductive material to form conductive contacts which for electrical contacts with the exposed portions of the sidewalls and tops of the conductive pad, thereby establishing electrical connections to the underlying conductive pad layer.