Method for depositing conformal nitrified tantalum silicide films by thermal CVD

• US 6,586,330 B1
• Filed: 05/07/2002
• Issued: 07/01/2003
• Est. Priority Date: 05/07/2002
• Status: Expired due to Fees

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Ludviksson, Audunn, Hillman, Joseph T.
• Primary Examiner(s): Niebling, John F.
• Assistant Examiner(s): GURLEY, LYNNE ANN
• Application Number:
  US10/140,538
• Time in Patent Office: 420 Days
• Field of Search: 438/643, 438/653, 438/680, 438/683, 438/685
• US Class Current: 438/643
• CPC Class Codes: C23C 16/42 Silicides
• CPC Class Codes: C23C 16/56 After-treatment
• CPC Class Codes: H01L 21/28518 the conductive layers comprising silicides H01L21/28537 takes precedence

Abstract

Method for depositing a nitrified tantalum silicide barrier film on a semiconductor device including a silicon-based substrate with recessed features by low temperature thermal CVD of tantalum silicide and subsequent nitrification. The nitrified tantalum silicide barrier film exhibits high conformality and low fluorine or chlorine impurity content. A specific embodiment of the method includes depositing tantalum silicide by TCVD from the reaction of a TaF₅ or TaCl₅ precursor vapor with silane gas on a 250° C.-450° C. heated substrate, then exposing the tantalum silicide to a thermal NH₃ treatment or an NH₃— or N₂-containing plasma treatment.

Claims

1. A method of depositing a nitrified tantalum silicide (TaSiN) barrier film on a semiconductor device substrate having a temperature in the range of about 250°

C.-450°

C., the method comprising;

depositing a TaSi_y film on said substrate by a thermal chemical vapor deposition (TCVD) process including providing a vapor of a precursor selected from the group consisting of TaF₅ and TaCl₅ to a reaction chamber containing said substrate by heating said precursor to a temperature sufficient to vaporize said precursor and combining said vapor with a process gas comprising silane,

then incorporating nitrogen into said TaSi_y film to form said TaSiN film by a method selected from the group consisting of;

a) exposing said TaSi_y film to a NH₃-containing plasma;

b) exposing said TaSi_y film to a N₂-containing plasma; and

c) exposing said TaSi_y film to a thermal NH₃-containing gas.

2. The method of claim 1, wherein said precursor is tantalum pentafluoride and heating said precursor includes heating to a temperature in the range of about 80°

C.-150°

C.

3. The method of claim 1, wherein said precursor is tantalum pentachloride and heating said precursor includes heating to a temperature in the range of about 130°

C.-150°

C.

4. The method of claim 1, wherein heating said precursor includes heating to a temperature sufficient to provide a vapor pressure of said precursor of at least 3 Torr.

5. The method of claim 1, wherein said vapor is provided at a flow rate in the range of about 1-50 sccm.

6. The method of claim 1, wherein said silane is provided to said reaction chamber at a flow rate in the range of about 0.01-10 slm.

7. The method of claim 6, wherein said process gas further comprises H₂ and is provided to said reaction chamber at a flow rate in the range of about 0.1-10 slm.

8. The method of claim 1, wherein said TaSi_y film deposition occurs at a pressure of said reaction chamber in the range of about 0.1-10 Torr.

9. The method of claim 1, further comprising depositing a copper layer on said substrate, wherein said TaSiN film is integral with said copper layer.

10. The method of claim 1, wherein said TaSi_y film is deposited at a rate of at least about 100 Å

min.

11. The method of claim 1, wherein said substrate comprises an integrated circuit containing a high aspect ratio feature.

12. The method of claim 1, wherein providing said vapor includes delivering said vapor to said reaction chamber substantially without a carrier gas.

13. The method of claim 1, wherein said incorporating nitrogen comprises the method (a) of exposing said TaSi_y film to a NH₃-containing plasma.

14. The method of claim 13, wherein said plasma is generated with a plasma power in the range of about 0.01-10 kW.

15. The method of claim 13, wherein said exposing in method (a) is for a time of about 2-600 seconds.

16. The method of claim 13, wherein said NH₃-containing plasma further includes N₂.

17. The method of claim 1, wherein said incorporating nitrogen comprises the method (b) of exposing said TaSi_y film to a N₂-containing plasma.

18. The method of claim 17, wherein said plasma is generated with a plasma power in the range of about 0.01-10 kW.

19. The method of claim 17, wherein said exposing of method (b) is for a time of about 2-600 seconds.

20. The method of claim 1, wherein said incorporating nitrogen comprises the method (c) of exposing said TaSi_y film to a thermal NH₃-containing gas.

21. The method of claim 20, wherein said exposing of method (c) is for a time of about 2-600 seconds.

22. The method of claim 1, wherein said depositing and said nitrogen incorporating steps are repeated to form a TaSiN film of desired thickness.

23. The method of claim 1, wherein said depositing step is effected to deposit a TaSi_y film up to about 100 Å

, followed by said nitrogen incorporating step, and said depositing and nitrogen incorporating steps are repeated until said TaSiN film is formed to a desired thickness.

24. A method of depositing a nitrified tantalum suicide (TaSiN) barrier film on a semiconductor device substrate having a temperature in the range of about 250°

C.-450°

C., the method comprising;

depositing a TaSi_y film on said substrate by a thermal chemical vapor deposition (TCVD) process including delivering a tantalum pentafluoride precursor to a reaction chamber containing said substrate without a carrier gas by heating said precursor to a temperature in the range of about 80°

C.-150°

C. sufficient to produce a vapor of said precursor to provide a pressure of at least about 3 Torr to deliver said vapor of said precursor and combining said vapor with a process gas comprising silane,

then incorporating nitrogen into said TaSi_y film to form said TaSiN film by a method selected from the group consisting of;

a) exposing said TaSi_y film to a NH₃-containing plasma;

b) exposing said TaSi_y film to a N₂-containing plasma; and

c) exposing said TaSi_y film to a thermal NH₃-containing gas.

25. The method of claim 24, wherein heating said precursor includes heating to a temperature of about 85°

C.

26. The method of claim 24, wherein said pressure to deliver said vapor is at least about 5 Torr.

27. The method of claim 24, wherein said TaSi_y film is deposited onto a silicon-based substrate having at least one recessed surface feature.

28. The method of claim 24, further comprising depositing a copper metallization layer on the TaSiN film.

29. The method of claim 24, wherein said incorporating nitrogen comprises the method (a) of exposing said TaSi_y film to a NH₃-containing plasma.

30. The method of claim 29, wherein said plasma is generated with a plasma power in the range of about 0.01-10 kW.

31. The method of claim 29, wherein said exposing of method (a) is for a time of about 2-600 seconds.

32. The method of claim 29, wherein said NH₃-containing plasma further includes N₂.

33. The method of claim 24, wherein said incorporating nitrogen comprises the method (b) of exposing said TaSi_y film to a N₂-containing plasma.

34. The method of claim 33, wherein said plasma is generated with a plasma power in the range of about 0.01-10 kW.

35. The method of claim 33, wherein said exposing of method (b) is for a time of about 2-600 seconds.

36. The method of claim 24, wherein said incorporating nitrogen comprises the method (c) of exposing said TaSi_y film to a thermal NH₃-containing gas.

37. The method of claim 36, wherein said exposing of method (c) is for a time of about 2-600 seconds.

38. The method of claim 24, wherein said depositing and nitrogen incorporating steps are repeated to form a TaSiN film of desired thickness.

39. The method of claim 24, wherein said depositing step is effected to deposit a TaSi_y film up to about 100 Å

, followed by said nitrogen incorporating step, and said depositing and nitrogen incorporating steps are repeated until said TaSiN film is formed to a desired thickness.

40. A method of depositing a nitrified tantalum silicide (TaSiN) barrier film on a semiconductor device substrate having a temperature in the range of about 250°

C.-450°

C., the method comprising;

depositing a TaSi_y film on said substrate by a thermal chemical vapor deposition (TCVD) process including delivering a tantalum pentachloride precursor to a reaction chamber containing said substrate without a carrier gas by heating said precursor to a temperature in the range of about 130°

C.-150°

C. sufficient to produce a vapor of said precursor to provide a pressure of at least about 3 Torr to deliver said vapor of said precursor and combining said vapor with a process gas comprising silane,

then incorporating nitrogen into said TaSi_y film to form said TaSiN film by a method selected from the group consisting of;

a) exposing said TaSi_y film to a NH₃-containing plasma;

b) exposing said TaSi_y film to a N₂-containing plasma; and

c) exposing said TaSi_y film to a thermal NH₃-containing gas.

41. The method of claim 40, wherein heating said precursor includes heating to a temperature of about 140°

C.

42. The method of claim 40, wherein said pressure to deliver said vapor is at least about 5 Torr.

43. The method of claim 40, wherein said TaSi_y film is deposited onto a silicon-based substrate having at least one recessed surface feature.

44. The method of claim 40, further comprising depositing a copper metallization layer on the TaSiN.

45. The method of claim 40, wherein said incorporating nitrogen comprises the method (a) of exposing said TaSi_y film to a NH₃-containing plasma.

46. The method of claim 45, wherein said plasma is generated with a plasma power in the range of about 0.01-10 kW.

47. The method of claim 45, wherein said exposing of method (a) is for a time of about 2-600 seconds.

48. The method of claim 45, wherein said NH₃-containing plasma further includes N₂.

49. The method of claim 40, wherein said incorporating nitrogen comprises the method (b) of exposing said TaSi_y film to a N₂-containing plasma.

50. The method of claim 49, wherein said plasma is generated with a plasma power in the range of about 0.01-10 kW.

51. The method of claim 49, wherein said exposing of method (b) is for a time of about 2-600 seconds.

52. The method of claim 40, wherein said incorporating nitrogen comprises the method (c) of exposing said TaSi_y film to a thermal NH₃-containing gas.

53. The method of claim 52, wherein said exposing of method (c) is for a time of about 2-600 seconds.

54. The method of claim 40, wherein said depositing and nitrogen incorporating steps are repeated to form a TaSiN film of desired thickness.

55. The method of claim 40, wherein said depositing step is effected to deposit a TaSi_y film up to about 100 Å

, followed by said nitrogen incorporating step, and said depositing and nitrogen incorporating steps are repeated until said TaSiN film is formed to a desired thickness.