Integrated circuit die having a copper contact and method therefor
View Patent ↗An integrated circuit die ( 10 ) has a copper contact ( 16, 18 ), which, upon exposure to the ambient air, forms a native copper oxide. An organic material is applied to the copper contact which reacts with the native copper oxide to form an organic coating ( 12, 14 ) on the copper contact in order to prevent further copper oxidation. In this manner, further processing at higher temperatures, such as those greater than 100 degrees Celsius, is not inhibited by excessive copper oxidation. For example, due to the organic coating, the high temperature of the wire bond process does not result in excessive oxidation which would prevent reliable wire bonding. Thus, the formation of the organic coating allows for a reliable and thermal resistance wire bond ( 32, 34 ). Alternatively, the organic coating can be formed over exposed copper at any time during the formation of the integrated circuit die to prevent or limit the formation of copper oxidation.
1. An integrated circuit die comprising:
a copper contact, wherein the copper contact is a wire bond pad;
a coating on the copper contact, the coating including a material formed from a reaction of an organic material with copper oxide.
2. The integrated circuit die of claim 1 wherein the coating is formed by exposing the copper contact to a solution that includes the organic material.
3. The integrated circuit of claim 2 wherein the solution has a pH level of at least 7.
4. The integrated circuit of claim 3 wherein the solution has a pH level of at least 7.5.
5. The integrated circuit of claim 1 wherein the organic material includes molecules having nitrogen-hydrogen bonds.
6. The integrated circuit of claim 1 wherein the organic material includes benzotriazole.
7. The integrated circuit of claim 1 wherein the organic material includes at least one of tolyltriazole, imidazoles, benzoimidazoles, polyaniline, and polyimidazoles.
8. The integrated circuit die of claim 1 further comprising:
a plurality of interconnect layers including a final copper interconnect layer;
an insulating layer overlying the interconnect layers;
wherein the copper contact is located in the final copper layer and is accessible by an opening in the insulating layer.
9. The integrated circuit die of claim 8 wherein the coating is located in the opening in the insulating layer.
10. The integrated circuit of claim 1 wherein the coating has a thermal resistance of 100 C or greater.
11. The integrated circuit of claim 1 wherein the coating has a thickness of 150 Angstrom or less.
12. The integrated circuit of claim 1 wherein the coating has a thickness in the range of 20-50 Angstroms.
13. The integrated circuit of claim 1 wherein the coating has a thickness of 50 Angstroms or less.
14. An integrated circuit package including the integrated circuit die of claim 1 and further comprising:
a package substrate, the integrated circuit die attached to the packaged substrate;
a wire connected to the copper contact and connected to a contact of the package substrate.
15. An integrated circuit die comprising:
a plurality of copper bond pads;
a coating on each of the plurality of copper bond pads, the coating formed from exposing the copper bond pads to a solution that includes an organic material, the organic material includes molecules having nitrogen hydrogen bonds, the coating includes a material formed from a reaction of the organic material with copper oxide, the coating has a thickness of 150 angstroms or less.