Barrier-metal-free copper damascene technology using atomic hydrogen enhanced reflow
View Patent ↗A method for forming conductive contacts and interconnects in a semiconductor structure, and the resulting conductive components are provided. In particular, the method is used to fabricate single or dual damascene copper contacts and interconnects in integrated circuits such as memory devices and microprocessor.
1. A method of forming a contact in an opening in an insulative material, comprising:
forming a non-metal barrier material over the insulative material within the opening;
depositing a conductive material over the non-metal barrier material to fill the opening; and
reflowing the conductive material in an atmosphere of atomic hydrogen at a temperature of less than about 400° C.
2. The method of claim 1 , wherein said depositing step is selected from the group consisting of ionized sputtering and evaporation.
3. The method of claim 2 , wherein said reflow step is performed at a temperature between 300° C. and 350° C.
4. The method of claim 3 , wherein said reflow step is performed at a temperature of substantially 320° C.
5. The method of claim 1 , wherein said atomic hydrogen is generated in a mixed high density inert gas/hydrogen plasma.
6. The method of claim 5 , wherein said plasma is formed with microwave excitation.
7. The method of claim 6 , wherein said excitation is performed at a pressure of about 1 Torr and a temperature of about 400° C.
8. The method of claim 5 , wherein the mixing ratio of hydrogen to inert gas is between 3% and 5%.
9. The method of claim 8 , wherein the inert gas is krypton.
10. A contact in an opening in an insulative material, produced by the process of:
forming a non-metal barrier material over the insulative material within the opening;
depositing a conductive material over the non-metal barrier material to fill the opening; and
reflowing the conductive material in an atmosphere of atomic hydrogen at a temperature of less than about 400° C.
11. The contact of claim 10 , wherein said depositing step is selected from the group consisting of ionized sputtering and evaporation.
12. The contact of claim 11 , wherein said reflow step is performed at a temperature between 300° C. and 350° C.
13. The contact of claim 12 , wherein said reflow step is performed at a temperature of substantially 320° C.
14. The contact of claim 10 , wherein said atomic hydrogen is generated in a mixed high density inert gas/hydrogen plasma.
15. The contact of claim 14 , wherein said plasma is formed with microwave excitation.
16. The contact of claim 15 , wherein said excitation is performed at a pressure of about 1 Torr and a temperature of about 400° C.
17. The contact of claim 14 , wherein the mixing ratio of hydrogen to inert gas is between 3% and 5%.
18. The contact of claim 17 , wherein the inert gas is krypton.
19. A contact in an opening in an insulative material, produced by the process of:
forming a non-metal barrier material over the insulative material within the opening;
depositing a conductive material over the non-metal barrier material to fill the opening selected from the group of ionized sputtering and metal evaporation;
and reflowing the conductive material in an atmosphere of atomic hydrogen at a temperature of substantially 320° C.