Methods of forming copper-based conductive structures on semiconductor devices
Disclosed herein are various methods of forming copper-based conductive structures on semiconductor devices, such as transistors. In one example, the method involves performing a first etching process through a patterned metal hard mask layer to define an opening in a layer of insulating material, performing a second etching process through the opening in the layer of insulating material that exposes a portion of an underlying copper-containing structure, performing a wet etching process to remove the patterned metal hard mask layer, performing a selective metal deposition process through the opening in the layer of insulating material to selectively form a metal region on the copper-containing structure and, after forming the metal region, forming a copper-containing structure in the opening above the metal region.
1. A method, comprising:
performing a first etching process through a patterned metal hard mask layer to define an opening in a layer of insulating material;
performing a second etching process through said opening in said layer of insulating material to thereby expose a portion of an underlying copper-containing structure;
after performing the second etching process, performing a wet etching process to remove said patterned metal hard mask layer;
performing a selective metal deposition process through said opening in said layer of insulating material to selectively form a metal region on said copper-containing structure; and
after forming said metal region, forming a copper-containing structure in said opening in said layer of insulating material above said metal region.
2. The method of claim 1 , wherein said patterned metal hard mask layer is comprised of titanium nitride, titanium, tantalum or tantalum nitride.
3. The method of claim 1 , wherein said wet etching process is performed using an oxidizing agent consisting of hydrogen peroxide or a mixture of ammonia and hydrogen peroxide.
4. The method of claim 1 , wherein performing said wet etching process to remove said patterned metal hard mask layer creates a void in said underlying copper-containing structure and wherein said metal region substantially fills said void.
5. The method of claim 1 , wherein said metal region is comprised of copper, manganese, aluminum or cobalt.
6. The method of claim 1 , wherein forming said copper-containing structure in said opening in said layer of insulating material above said metal region comprises:
forming a barrier layer in said opening in said layer of insulating material that contacts said metal region; and
forming a copper region in said opening in said layer of insulating material above said barrier layer.
7. The method of claim 1 , wherein performing said selective metal deposition process comprises performing a chemical vapor deposition process or an atomic layer deposition process to form said metal region.
8. The method of claim 1 , wherein said layer of insulating material is comprised of a low-k insulating material.
9. The method of claim 1 , wherein performing said selective metal deposition process comprises performing said selective metal deposition process at a temperature within the range of about 50-400° C. and at a pressure within the range of about 0.1-50 Torr using a metal-containing precursor.
10. A method, comprising:
performing a first etching process through a patterned metal hard mask layer to define an opening in a layer of insulating material;
performing a second etching process through said opening in said layer of insulating material to thereby expose a portion of an underlying copper-containing structure;
after performing the second etching process, performing a wet etching process to remove said patterned metal hard mask layer, said wet etching process resulting in the formation of a void in said underlying copper-containing structure;
performing a selective metal deposition process through said opening in said layer of insulating material to selectively form a metal region that substantially fills said void in said copper-containing structure; and
after forming said metal region, forming a copper-containing structure in said opening in said layer of insulating material above said metal region.
11. The method of claim 10 , wherein said patterned metal hard mask layer is comprised of titanium nitride, titanium, tantalum or tantalum nitride.
12. The method of claim 10 , wherein said wet etching process is performed using an oxidizing agent consisting of hydrogen peroxide or a mixture of ammonia and hydrogen peroxide.
13. The method of claim 10 , wherein said metal region is comprised of copper, manganese, aluminum or cobalt.
14. The method of claim 10 , wherein forming said copper-containing structure in said opening in said layer of insulating material above said metal region comprises:
forming a barrier layer in said opening in said layer of insulating material that contacts said metal region; and
forming a copper region in said opening in said layer of insulating material above said barrier layer.
15. The method of claim 10 , wherein performing said selective metal deposition process comprises performing a chemical vapor deposition process or an atomic layer deposition process to form said metal region.
16. The method of claim 10 , wherein said layer of insulating material is comprised of a low-k insulating material.
17. The method of claim 10 , wherein performing said selective metal deposition process comprises performing said selective metal deposition process at a temperature within the range of about 50-400° C. and at a pressure within the range of about 0.1-50 Torr using a metal-containing precursor.
18. A method, comprising:
performing a first etching process through a patterned metal hard mask layer to define an opening in a layer of insulating material;
performing a second etching process through said opening in said layer of insulating material to thereby expose a portion of an underlying copper-containing structure;
after performing the second etching process, performing a wet etching process to remove said patterned metal hard mask layer, said wet etching process resulting in the formation of a void in said underlying copper-containing structure;
performing a selective metal deposition process through said opening in said layer of insulating material to selectively form a metal region that substantially fills said void in said copper-containing structure, wherein said selective metal deposition process is one of a chemical vapor deposition process or an atomic layer deposition process and wherein said selective metal deposition process is performed at a temperature within the range of about 50-400° C. and at a pressure within the range of about 0.1-50 Torr using a metal-containing precursor; and
after forming said metal region, forming a copper-containing structure in said opening in said layer of insulating material above said metal region.
19. The method of claim 18 , wherein said patterned metal hard mask layer is comprised of titanium nitride, titanium, tantalum or tantalum nitride.
20. The method of claim 18 , wherein said wet etching process is performed using an oxidizing agent consisting of hydrogen peroxide or a mixture of ammonia and hydrogen peroxide.
21. The method of claim 18 , wherein said metal region is comprised of copper, manganese, aluminum or cobalt.
22. The method of claim 18 , wherein forming said copper-containing structure in said opening in said layer of insulating material above said metal region comprises:
forming a barrier layer in said opening in said layer of insulating material that contacts said metal region; and
forming a copper region in said opening in said layer of insulating material above said barrier layer.