Tantalum nitride CVD deposition by tantalum oxide densification

• US 6,638,810 B2
• Filed: 11/05/2001
• Issued: 10/28/2003
• Est. Priority Date: 02/22/2000
• Status: Expired due to Fees

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Ghanayem, Steve G., Bakli, Mouloud, Tran, Huyen T.
• Primary Examiner(s): Niebling, John F.
• Assistant Examiner(s): Gurley, Lynne Ann
• Application Number:
  US10/015,203
• Publication Number:
  US 20030008501A1
• Time in Patent Office: 722 Days
• Field of Search: 438/240, 438/396, 438/408, 438/635, 438/660, 438/663, 438/785
• US Class Current: 438/240
• CPC Class Codes: C23C 16/0281 of metallic sub-layers C23C16/029 takes precedence
• CPC Class Codes: C23C 16/405 of refractory metals or yttrium
• CPC Class Codes: C23C 16/56 After-treatment
• CPC Class Codes: H01L 21/02183 the material containing tantalum, e.g. Ta2O5
• CPC Class Codes: H01L 21/02205 the layer being characterised by the precursor material for deposition
• CPC Class Codes: H01L 21/02266 deposition by physical ablation of a target, e.g. sputtering, reactive sputtering, physical vapour deposition or pulsed laser deposition
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• CPC Class Codes: H01L 21/02332 into an oxide layer, e.g. changing SiO to SiON
• CPC Class Codes: H01L 21/31604 Deposition from a gas or vapour H01L21/31691, H01L21/31695 take precedence
• CPC Class Codes: H01L 21/318 composed of nitrides
• CPC Class Codes: H01L 29/66181 Conductor-insulator-semiconductor capacitors, e.g. trench capacitors
• CPC Class Codes: H10B 12/0387 Making the trench

Abstract

The invention provides a method for forming a metal nitride film by depositing a metal oxide film on the substrate and exposing the metal oxide film to a nitrating gas to densify the metal oxide and form a metal nitride film. The metal oxide film is deposited by the decomposition of a chemical vapor deposition precursor. The nitrating step comprises exposing the metal oxide film to a thermally or plasma enhanced nitrating gas preferably comprising nitrogen, oxygen, and ammonia. The invention also provides a process for forming a liner/barrier scheme for a metallization stack by forming a metal nitride layer over the substrate by the densification of a metal oxide layer by a nitrating gas depositing a metal liner layer. Optionally, a metal liner layer may be deposited over substrate prior to the metal nitride layer to forma metal/metal nitride liner/barrier scheme. The invention further provides a process to form a microelectronic device comprising forming a first electrode, forming a metal nitride layer over the first electrode by densifying a metal oxide layer by a nitrating gas to form a metal nitride layer, depositing a dielectric layer over the metal nitride layer, and forming a second electrode over the dielectric layer. Alternatively, the metal nitride film may comprise the first and second electrodes.

Claims

1. A method tor processing a substrate comprising:

depositing a metal oxide film or a metal oxynitride film on the substrate; and

exposing the metal oxide film or the metal oxynitride film to a nitrating gas to fully convert the metal oxide film or the metal oxynitride film to a metal nitride film.

2. The method of claim 1, wherein the metal oxide film comprises tantalum oxide, the metal oxynitride film comprises tantalum oxynitride and the metal nitride film comprises tantalum nitride (Ta_XN_Y).

3. The method of claim 1, wherein the metal oxide film or the metal oxynitride film is deposited by chemical vapor deposition of a precursor selected from the group consisting of pentaethoxytantalum (Ta(OC₂H₅)₅), cyclopentane tantalum azide, tantalum pentachloride, Ta(OCH₃), and combinations thereof.

4. The method of claim 1, wherein the nitrating gas is selected from the group consisting of nitrogen, ammonia, and nitrous oxide.

5. The method of claim 4, wherein the nitrating gas further comprises a gas selected from the group consisting of oxygen, hydrogen, and combinations thereof.

6. The method of claim 1, wherein nitrating the metal oxide film or the metal oxynitride layer comprises heating the metal oxide film or the metal oxynitride layer at a temperature between about 200°

C. and about 800°

C. in the nitrating gas.

7. The method of claim 1, wherein nitrating the metal oxide film or the metal oxynitride layer comprises generating a plasma by applying power to a processing chamber at between about 25 and about 2000 Watts.

8. The method of claim 1, wherein the nitrating gas comprises nitrogen and a gas selected from the group of ammonia, nitrous oxide, hydrogen, oxygen, and combinations thereof.

9. The method of claim 1, wherein the metal oxide film or the metal oxynitride layer is heated for a period of between about 30 seconds and 180 seconds.

10. The method of claim 1, wherein the metal oxide or the metal oxynitride layer is deposited in the presence of a nitrogen containing gas.

11. The method of claim 10, wherein the nitrogen containing gas is selected from the group consisting of nitrogen, nitrous oxide, ammonia, and combinations thereof.

12. The method of claim 10, wherein the nitrating gas is selected from the group consisting of nitrogen, ammonia, nitrous oxide, and combinations thereof.

13. The method of claim 10, wherein the nitrating gas comprises nitrogen and a gas selected from the group of ammonia, nitrous oxide, hydrogen, oxygen, and combinations thereof.

14. The method of claim 10, wherein the metal oxide film is deposited by chemical vapor deposition of a precursor selected from the group consisting of pentaethoxytantalum (Ta(OC₂H₅)₅), cyclopentane tantalum azide, tantalum pentachloride, Ta(OCH₃), and combinations thereof.

15. The method of claim 1, wherein the metal oxide film is densified during the conversion to the metal nitride film.

16. A method for forming a feature on a substrate comprising:

depositing a dielectric layer on the substrate;

etching an aperture within the dielectric layer to expose the substrate;

depositing a metal oxide layer or a metal oxynitride layer on the substrate; and

exposing the metal oxide layer or the metal oxynitride layer to a nitrating gas to fully convert the metal oxide layer or the metal oxynitride layer to a metal nitride layer.

17. The method of claim 16, further comprising depositing a metal layer prior to depositing the metal oxide layer.

18. The method of claim 16, wherein the metal oxide layer comprises tantalum oxide, the metal oxynitride layer comprises tantalum oxynitride and the metal nitride layer comprises tantalum nitride.

19. The method of claim 16, wherein the metal oxide layer or the metal oxynitride layer is deposited by chemical vapor deposition of a precursor selected from the group consisting of pentaethoxytantalum (Ta(OC₂H₅)₅), cyclopentane tantalum azide, tantalum pentachloride, Ta(OCH₃), and combinations thereof.

20. The method of claim 16, wherein the nitrating gas is selected from the group consisting of nitrogen, ammonia, and nitrous oxide.

21. The method of claim 20, wherein the nitrating gas further comprises a gas selected from the group consisting of oxygen, hydrogen, and combinations thereof.

22. The method of claim 16, wherein fully converting the metal oxide layer or the metal oxynitride layer to the metal nitride comprises heating the metal oxide layer or the metal oxynitride layer at a temperature between about 200°

C. and about 800°

C. in the nitrating gas.

23. The method of claim 16, wherein fully converting the metal oxide layer or the metal oxynitride layer to the metal nitride comprises generating a plasma by applying a power of between about 25 and about 2000 Watts.

24. The method of claim 16, further comprising depositing a conductive metal layer on the metal nitride layer.

33. The method of claim 24, wherein the high dielectric constant material is tantalum oxide (Ta₂O₅).

25. A method for forming a microelectronic device, comprising:

forming a first electrode;

depositing a metal nitride layer over the first electrode, comprising;

depositing a metal oxide layer or a metal oxynitride layer on a substrate; and

exposing the metal oxide layer or the metal oxynitride layer to a nitrating gas to fully convert the metal oxide layer or the metal oxynitride layer to a metal nitride layer;

depositing a dielectric layer over the metal nitride layer; and

forming a second electrode over the dielectric layer.

26. The method of claim 25, wherein the metal oxide layer comprises tantalum oxide, the metal oxynitride layer comprises tantalum oxynitride and the metal nitride layer comprises tantalum nitride.

27. The method of claim 25, wherein the metal oxide layer or the metal oxynitride layer is deposited by chemical vapor deposition of a precursor selected from the group consisting of pentaethoxytantalum (Ta(OC₂H₅)₅), cyclopentane tantalum azide, tantalum pentachloride, Ta(OCH₃), and combinations thereof.

28. The method of claim 25, wherein the nitrating gas is selected from the group consisting of nitrogen, ammonia, and nitrous oxide.

29. The method of claim 28, wherein the nitrating gas further comprises a gas selected from the group consisting of oxygen, hydrogen, and combinations thereof.

30. The method of claim 29, wherein nitrating the metal oxide layer or the metal oxynitride layer comprises heating the layer at a temperature between about 200°

C. and about 800°

C. in the nitrating gas.

31. The method of claim 25, wherein nitrating the metal oxide layer comprises striking a plasma, the plasma comprising capacitively or inductively coupling energy into a processing chamber at a power between about 25 and about 2000 Watts.

32. The method of claim 25, wherein the dielectric layer comprises a high dielectric constant material.

34. The method of claim 25, wherein the metal nitride layer and the dielectric layer are deposited sequentially in the same chamber.

35. The method of claim 25, wherein the metal nitride layer and the dielectric layer are deposited from the same precursor.

36. The method of claim 25, further comprising annealing the substrate at between about 300°

C. and about 600°

C. for between about 5 minutes and about 50 minutes in a conventional anneal furnace.

37. The method of claim 25, further comprising annealing the substrate at between about 500°

C. and about 800°

C. for between about 30 seconds and about 120 seconds in a rapid thermal anneal processor.

38. The method of claim 25, further comprising:

depositing a metal nitride layer between the dielectric layer and the second electrode, comprising;

depositing a metal oxide layer or a metal oxynitride layer on the substrate; and

exposing the metal oxide layer or the metal oxynitride layer to a nitrating gas to fully convert the metal oxide layer or the metal oxynitride layer to a metal nitride layer.

39. The method of claim 38, wherein the metal oxide layer comprises tantalum oxide (Ta₂O₅) and the metal nitride layer comprises tantalum nitride (Ta_XN_Y).

40. The method of claim 38, wherein the metal nitride layer and the dielectric layer are deposited from the same precursor.

41. The method of claim 25, wherein the nitrating gas comprises nitrogen and a gas selected from the group of ammonia, nitrous oxide, hydrogen, oxygen, and combinations thereof.

42. The method of claim 25, wherein the metal oxide or the metal oxynitride layer is deposited in the presence of a nitrogen containing gas.

43. The method of claim 42, wherein the nitrogen containing gas is selected from the group consisting of nitrogen, nitrous oxide, ammonia, and combinations thereof.

44. The method of claim 42, wherein the nitrating gas is selected from the group consisting of nitrogen, ammonia, nitrous oxide, and combinations thereof.

45. The method of claim 42, wherein the nitrating gas comprises nitrogen and a gas selected from the group of ammonia, nitrous oxide, hydrogen, oxygen, and combinations thereof.

46. The method of claim 42, wherein the metal oxide film or the metal oxynitride layer is deposited by chemical vapor deposition of a precursor selected from the group consisting of pentaethoxytantalum (Ta(OC₂H₅)₅), cyclopentane tantalum azide, tantalum pentachloride, Ta(OCH₃), and combinations thereof.