High speed, high density, low power die interconnect system
A system for interconnecting at least two die each die having a plurality of conducting layers and dielectric layers disposed upon a substrate which may include active and passive elements. In one embodiment there is at least one interconnect coupling at least one conducting layer on a side of one die to at least one conducting layer on a side of the other die. Another interconnect embodiment is a slug having conducting and dielectric layers disposed between two or more die to interconnect between the die. Other interconnect techniques include direct coupling such as rod, ball, dual balls, bar, cylinder, bump, slug, and carbon nanotube, as well as indirect coupling such as inductive coupling, capacitive coupling, and wireless communications. The die may have features to facilitate placement of the interconnects such as dogleg cuts, grooves, notches, enlarged contact pads, tapered side edges and stepped vias.
1. A method for forming a die, the method comprising:
forming a conducting layer;
forming a plurality of interposed conducting layers separated by a plurality of interposed dielectric layers, wherein the plurality of interposed conducting layers and the plurality of interposed dielectric layers are interposed between the conducting layer and a top surface of the die; and
forming a contact pad electrically connected by an electrical connection to one of the plurality of conducting layers and extending to a lateral edge of the die, wherein:
the electrical connection does not traverse all of the plurality of interposed conducting layers and all of the plurality of interposed dielectric layers; and
the contact pad comprises a tapered contact pad.
2. The method of claim 1 , wherein said forming a contact pad comprises forming a stepped via.
3. The method of claim 2 , wherein said forming a stepped via comprises:
forming hole in a dielectric layer; and
filling the hole with a conductive material to form a part of the stepped via.
4. The method of claim 3 , wherein the conductive material comprises copper.
5. The method of claim 3 , wherein the conductive material comprises a refractory metal.
6. The method of claim 3 , wherein said filling the hole with a conductive material is performed when an abutting conductive layer is formed.
7. The method of claim 2 , wherein said forming a stepped via comprises:
forming a plurality of holes in a corresponding plurality of dielectric layers; and
filling each of the plurality of holes with a conductive material to form a part of the stepped via.
8. The method of claim 7 , wherein the conductive material comprises copper.
9. The method of claim 7 , wherein the conductive material comprises a refractory metal.
10. The method of claim 7 , wherein each of the plurality of holes is filled with a conductive material when an abutting conductive layer is formed.
11. The method of claim 7 , wherein a portion of the plurality of holes are sized differently from each other.
12. The method of claim 11 , wherein the portion of the plurality of holes are sized differently from each other to contribute to a formation a flange in the tapered contact.
13. The method of claim 2 , wherein said forming a stepped via comprises:
forming a plurality of stepped via conducting layer portions; and
forming a plurality of stepped via dielectric layer portions.
14. The method of claim 1 , wherein the contact pad comprises an input/output (“I/O”) pad.