Multilayered contact structure having nickel, copper, and nickel-iron layers
A three dimensional multi-die package includes a first die and second die. The first die includes a contact attached to solder. The second die is thinned by adhesively attaching a handler to a top side of the second die and thinning a bottom side of the second die. The second die includes a multilayer contact of layered metallurgy that inhibits transfer of adhesive thereto. The layered metallurgy includes at least one layer that is wettable to the solder. The multilayer contact may include a Nickel layer, a Copper layer upon the Nickel layer, and a Nickel-Iron layer upon the Copper layer. The multilayer contact may also include a Nickel layer, a Copper-Tin layer upon the Nickel layer, and a Tin layer upon the Copper-Tin layer.
1. A semiconductor device fabrication method comprising:
forming a barrier layer upon a dielectric layer;
forming an electrically conductive plating layer upon the barrier layer, and;
forming a multilayered contact upon the plating layer by plating a first Nickel layer upon the plating layer, plating a Copper layer upon the first Nickel layer, plating a second Nickel layer upon the Copper layer, and plating a Nickel-Iron layer upon the second Nickel layer,
wherein the barrier layer is a first thickness;
the plating layer is a second thickness; and
each of the first Nickel layer, the Copper layer, the second Nickel layer, and the Nickel-Iron layer is a third thickness different than the first thickness and the second thickness.
2. The semiconductor device fabrication method of claim 1 , further comprising:
attaching a handler wafer to the multilayered contact side of the semiconductor device with adhesive.
3. The semiconductor device fabrication method of claim 1 , further comprising:
forming a photoresis upon the conductive layer;
forming an contact trench in the photoresist layer, the contact trench exposing a portion of the plating layer;
forming the multilayered contact structure within the contact trench, and;
removing the photoresist.
4. The semiconductor device fabrication method of claim 1 , further comprising:
removing portions of the conductive layer exterior to the multilayered contact structure, such that sidewalls of the conductive layer are coplanar with sidewalls a particular layer of the multilayered contact.
5. The semiconductor device fabrication method of claim 1 , further comprising:
removing portions of the barrier layer exterior to the multilayered contact structure, such that sidewalls of the barrier layer are coplanar with sidewalls a particular layer of the multilayered contact.
6. The semiconductor device fabrication method of claim 1 , wherein the semiconductor device is a thinned die and wherein at least one layer of the multilayer contact is wettable to solder electrically connected a second die in a three dimensional package.
7. The semiconductor device fabrication method of claim 1 , wherein the Nickel-Iron layer is a topmost layer of the multilayered contact.
8. The semiconductor device fabrication method of claim 7 , further comprising applying solder to a top surface of the Nickel-Iron layer.
9. The semiconductor device fabrication method of claim 1 , further comprising:
forming the dielectric layer upon a substrate;
forming a metal line in the dielectric layer; and
forming a via between and contacting the metal line and the barrier layer.
10. The semiconductor device fabrication method of claim 1 , wherein sidewalls of the barrier layer, the plating layer, the first Nickel layer, the Copper layer, the second Nickel layer, and the Nickel-Iron layer are all coplanar.
11. A semiconductor device fabrication method comprising:
forming a barrier layer upon a dielectric layer;
forming an electrically conductive plating layer upon the barrier layer, and;
forming a multilayered contact upon the plating layer, the multilayered contact comprising: a first Nickel layer upon the plating layer, a Copper layer upon the first Nickel layer, a second Nickel layer upon the Copper layer, and a Nickel-Iron layer upon the second Nickel layer,
wherein the barrier layer is a first thickness;
the plating layer is a second thickness; and
each of the first Nickel layer, the Copper layer, the second Nickel layer, and the Nickel-Iron layer is a third thickness different than the first thickness and the second thickness.
12. The semiconductor device fabrication method of claim 11 , wherein the Nickel-Iron layer is a topmost layer of the multilayered contact.
13. The semiconductor device fabrication method of claim 12 , further comprising applying solder to a top surface of the Nickel-Iron layer.
14. The semiconductor device fabrication method of claim 11 , further comprising:
forming the dielectric layer upon a substrate;
forming a metal line in the dielectric layer; and
forming a via between and contacting the metal line and the barrier layer.
15. The semiconductor device fabrication method of claim 11 , wherein sidewalls of the barrier layer, the plating layer, the first Nickel layer, the Copper layer, the second Nickel layer, and the Nickel-Iron layer are all coplanar.