Method of using NF3 for removing surface deposits from the interior of chemical vapor deposition chambers

• US 20070107750A1
• Filed: 11/07/2006
• Published: 05/17/2007
• Est. Priority Date: 11/14/2005
• Status: Abandoned Application

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Bai, Bo, Sawin, Herbert, An, Ju
• Application Number:
  US11/593,960
• Publication Number:
  US 20070107750A1
• Time in Patent Office: Days
• US Class Current: 134/1.100
• CPC Class Codes: C23C 16/4405 Cleaning of reactor or parts inside the reactor by using reactive gases
• CPC Class Codes: C23C 16/452 by activating reactive gas streams before their introduction into the reaction chamber, e.g. by ionisation or addition of reactive species

Abstract

The present invention relates to a remote plasma cleaning method for removing surface deposits from a surface, such as the interior of a depositions chamber that is used in fabricating electronic devices. The process involves activating a gas stream comprising an oxygen source, NF₃, and a fluorocarbon and contacting the activated gas mixture with surface deposits to remove the surface deposits.

Claims

1. A method for removing surface deposits, comprising:

(a) activating in a remote chamber a gas mixture comprising oxygen, a fluorocarbon, and NF₃, wherein the molar ratio of oxygen;

fluorocarbon is at least about 0.75;

1, and wherein the molar percentage of NF₃ in the said gas mixture is from about 50% to about 98%,

(b) allowing said activated gas mixture to flow into a process chamber, and thereafter,

(c) contacting said activated gas mixture with the surface deposits and thereby removing at least some of said deposits.

3. The method of claim 1 wherein the fluorocarbon is a perfluorocarbon.

4. The method of claim 1 wherein the fluorocarbon is selected from the group consisting of tetrafluoromethane, hexafluoroethane, octafluoropropane, perfluorotetrahydrofuran and octafluorocyclobutane.

5. The method of claim 3 wherein the fluorocarbon is hexafluoroethane.

6. The method of claim 3 wherein the fluorocarbon is octafluorocyclobutane.

7. The method of claim 1 wherein the said surface deposit a nitrogen-containing deposit.

8. The method of claim 1 wherein the said surface deposit is selected from the group consisting of silicon nitride, silicon oxynitride, silicon carbonitride, tungsten nitride, titanium nitride, and tantalum nitride.

9. The method of claim 7 wherein the said surface deposit is silicon nitride.

10. The method of claim 1 wherein the molar percentage of NF₃ is from about 60% to about 98% of the gas mixture.

11. The method of claim 1 wherein the molar percentage of NF₃ is from about 70% to about 90% of the gas mixture.

12. The method of claim 1 wherein the oxygen:

fluorocarbon molar ratio is about 1;

1.

13. The method of claim 1 wherein said gas mixture further comprises a carrier gas.

14. The method of claim 13 wherein said carrier gas is selected from the group consisting of argon and helium.

15. The method of claim 1 wherein the pressure in the process chamber is from about 0.5 torr to about 15 torr.

16. The method of claim 1 wherein the pressure in the remote chamber is from about 0.5 torr to about 15 torr.

17. The method of claim 16 wherein the pressure in the remote chamber is from about 2 torr to about 6 torr.

18. The method of claim 1 wherein said power is generated by an RF source, a DC source or a microwave source.

19. The method of claim 18 wherein said power is generated by an RF source.

20. A method for removing surface deposits comprising:

a.) activating in a process chamber a gas mixture comprising oxygen, a fluorocarbon, and NF₃, wherein the molar ratio of oxygen;

fluorocarbon is at least about 0.75;

1, and wherein the molar percentage of NF₃ in the said gas mixture is from about 50% to about 98%,

b.) contacting said activated gas mixture with the surface deposits and thereby removing at least some of said deposits.

21. A method as in claim 20 wherein said process chamber is the interior of a deposition chamber that is used in fabricating electronic devices.

22. The method of claim 20 wherein the fluorocarbon is a perfluorocarbon.

23. The method of claim 20 wherein the fluorocarbon is selected from the group consisting of tetrafluoromethane, hexafluoroethane, octafluoropropane, perfluorotetrahydrofuran and octafluorocyclobutane.

24. The method of claim 23 wherein the fluorocarbon is hexafluoroethane.

25. The method of claim 23 wherein the fluorocarbon is octafluorocyclobutane.

26. The method of claim 20 wherein the said surface deposit a nitrogen-containing deposit.

27. The method of claim 20 wherein the said surface deposit is selected from the group consisting of silicon nitride, silicon oxynitride, silicon carbonitride, tungsten nitride, titanium nitride, and tantalum nitride.

28. The method of claim 26 wherein the said surface deposit is silicon nitride.

29. The method of claim 20 wherein the molar ratio of oxygen:

fluorocarbon is at least about 1;

1.

30. The method of claim 20 wherein the molar percentage of NF₃ is from about 60% to about 98% of the gas mixture.

31. The method of claim 20 wherein the molar percentage of NF₃ is from about 70% to about 90% of the gas mixture.

32. The method of claim 20 wherein the oxygen:

fluorocarbon molar ratio is about 1;

1.

33. The method of claim 20 wherein said gas mixture further comprises a carrier gas.

34. The method of claim 33 wherein said carrier gas is selected from the group consisting of argon and helium.

2. The method of claim 1 wherein said process chamber is the interior of a deposition chamber that is used in fabricating electronic devices.

35. The method of claim 20 wherein the pressure in the process chamber is from about 0.5 torr to about 15 torr.

36. A cleaning gas mixture as in claim 34 wherein the fluorocarbon is a perfluorocarbon.

37. A cleaning gas mixture as in claim 36 wherein the perfluorocarbon is selected from the group consisting of tetrafluoromethane, hexafluoroethane, octafluoropropane, perfluorotetrahydrofuran and octafluorocyclobutane.

38. A cleaning gas mixture as in claim 36 wherein the perfluorocarbon is hexafluoroethane.

39. A cleaning gas mixture as in claim 36 wherein the perfluorocarbon is octafluorocyclobutane.

40. A cleaning gas mixture as in claim 35 wherein the oxygen:

fluorocarbon ratio is at least about 0.75;

1.0.

41. A cleaning gas mixture as in claim 35 wherein the oxygen:

fluorocarbon ratio is at least about 1;

1.

34-1. A cleaning gas mixture comprising from about 50% to about 98% on a molar basis NF₃, an oxygen source and a fluorocarbon.

35-2. A cleaning gas mixture as in claim 34 wherein the oxygen source is molecular oxygen.