Semiconductor die contact structure and method
A system and method for forming a semiconductor die contact structure is disclosed. An embodiment comprises a top level metal contact, such as copper, with a thickness large enough to act as a buffer for underlying low-k, extremely low-k, or ultra low-k dielectric layers. A contact pad or post-passivation interconnect may be formed over the top level metal contact, and a copper pillar or solder bump may be formed to be in electrical connection with the top level metal contact.
1. A semiconductor device comprising:
a substrate comprising a plurality of dielectric layers and conductive layers;
a metal contact in physical connection with an uppermost one of the plurality of conductive layers, the metal contact having a constant composition and a thickness greater than about 15,000 Å;
a first passivation layer over the metal contact;
a contact pad extending through the first passivation layer to make physical contact with the metal contact, the contact pad having a smaller width than the metal contact;
a second passivation layer over and in contact with a top surface of the contact pad; and
a connector in electrical connection with the metal contact.
2. The semiconductor device of claim 1 , wherein the connecter is a conductive pillar.
3. The semiconductor device of claim 2 , further comprising a post-passivation interconnect connecting the metal contact with the conductive pillar.
4. The semiconductor device of claim 3 , wherein the post-passivation interconnect comprises aluminum.
5. The semiconductor device of claim 1 , wherein the contact pad comprises aluminum.
6. The semiconductor device of claim 1 , wherein the connector is located directly over the metal contact.
7. The semiconductor device of claim 1 , wherein the connector is in direct contact with the metal contact.
8. The semiconductor device of claim 1 , wherein the connector is a solder bump.
9. A semiconductor device comprising:
a substrate comprising a plurality of metal layers;
a metal contact sharing an interface with the uppermost one of the plurality of metal layers, wherein the metal contact comprises a first region with a first material throughout the first region, the first region having a thickness greater than about 15,000 Å;
a first passivation layer over the metal contact;
a contact pad in physical connection with the metal contact and extending in a direction parallel with a major surface of the substrate no further than the metal contact;
a second passivation layer over the metal contact and the contact pad; and
a conductive pillar in electrical contact with the metal contact.
10. The semiconductor device of claim 9 , wherein the conductive pillar is a copper pillar.
11. The semiconductor device of claim 9 , wherein the metal contact comprises copper.
12. The semiconductor device of claim 9 , wherein the contact pad comprises aluminum.
13. The semiconductor device of claim 9 , wherein the metal contact has a thickness greater than about 20,000 Å.
14. The semiconductor device of claim 9 , wherein the metal contact is underlying and in direct contact with the conductive pillar.
15. The semiconductor device of claim 9 , further comprising a post-passivation interconnect connecting the metal contact with the conductive pillar.
16. The semiconductor device of claim 15 , wherein the post-passivation interconnect comprises aluminum.
17. A semiconductor device comprising:
a plurality of metal layers over a substrate;
a metal contact in physical contact with a conductive region of the plurality of metal layers, the metal contact having a single metal with a thickness greater than about 15,000 Å;
a first passivation layer over the metal contact;
a contact pad at least partially over the first passivation layer and in physical contact with the metal contact, the contact pad having a first width and the metal contact having a second width greater than the first width; and
a second passivation layer over the contact pad;
a conductive pillar in electrical contact with the metal contact.
18. The semiconductor device of claim 17 , wherein the metal contact comprises copper.