Metal nitride deposition by ALD with reduction pulse

• US 20030082296A1
• Filed: 09/12/2002
• Published: 05/01/2003
• Est. Priority Date: 09/14/2001
• Status: Active Grant

• Current Assignee: ASM International NV
• Original Assignee: ASM International NV
• Inventors: Li, Wei-Min, Elers, Kai
• Granted Patent: US 6,986,914 B2
• Time in Patent Office: Days
• US Class Current: 174/256
• CPC Class Codes: C23C 16/34 Nitrides C23C16/303 takes precedence
• CPC Class Codes: C23C 16/36 Carbonitrides
• CPC Class Codes: C23C 16/45529 specially adapted for making a layer stack of alternating different compositions or gradient compositions
• CPC Class Codes: C23C 16/45531 specially adapted for making ternary or higher compositions
• CPC Class Codes: C23C 16/45534 Use of auxiliary reactants other than used for contributing to the composition of the main film, e.g. catalysts, activators or scavengers
• CPC Class Codes: H01L 21/28562 Selective deposition
• CPC Class Codes: H01L 21/28568 the conductive layers comprising transition metals H01L21/28518 takes precedence
• CPC Class Codes: H01L 21/76807 for dual damascene structures
• CPC Class Codes: H01L 21/76838 characterised by the formation and the after-treatment of the conductors etching for patterning the conductors H01L21/3213
• CPC Class Codes: H01L 21/76843 formed in openings in a dielectric
• CPC Class Codes: H01L 21/76846 Layer combinations
• CPC Class Codes: H01L 21/76862 Bombardment with particles, e.g. treatment in noble gas plasmas; UV irradiation
• CPC Class Codes: H01L 21/76871 Layers specifically deposited to enhance or enable the nucleation of further layers, i.e. seed layers
• CPC Class Codes: H01L 21/76873 for electroplating
• CPC Class Codes: H01L 21/76874 for electroless plating
• CPC Class Codes: H01L 21/76876 for deposition from the gas phase, e.g. CVD
• CPC Class Codes: H01L 2221/1089 Stacks of seed layers
• CPC Class Codes: H01L 23/53238 Additional layers associated with copper layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: Y10T 428/24331 : including nonapertured component

Abstract

The present methods provide tools for growing conformal metal thin films, including metal nitride, metal carbide and metal nitride carbide thin films. In particular, methods are provided for growing such films from aggressive chemicals. The amount of corrosive chemical compounds, such as hydrogen halides, is reduced during the deposition of transition metal, transition metal carbide, transition metal nitride and transition metal nitride carbide thin films on various surfaces, such as metals and oxides. Getter compounds protect surfaces sensitive to hydrogen halides and ammonium halides, such as aluminum, copper, silicon oxide and the layers being deposited, against corrosion. Nanolaminate structures incorporating metallic thin films, and methods for forming the same, are also disclosed.

Claims

1. A method of forming a metallic thin film on the surface of a substrate within a reaction space by an atomic layer deposition (ALD) type process, wherein the ALD type process comprises providing alternating pulses of reactants in a plurality of deposition cycles, each cycle comprising supplying:

a metal halide reactant;

a second reactant comprising a species to be included in the metallic thin film; and

a third reactant that is capable of gettering halides from the monolayer,

wherein the third reactant sequentially does not immediately follow the metal halide reactant and wherein excess reactant and/or reactant byproducts are removed from the reaction space prior to supplying the next reactant.

2. The method of claim 1, wherein the second reactant comprises nitrogen.

3. The method of claim 2, wherein the second reactant comprises ammonia.

4. The method of claim 1, wherein the second reactant comprises carbon.

5. The method of claim 1, wherein the metal halide is a metal fluoride.

6. The method of claim 5, wherein the metal halide is WF₆.

7. The method of claim 1, wherein the surface comprises metal.

8. The method of claim 7, wherein the surface comprises copper.

9. The method of claim 7, wherein the surface further comprises a form of silicon oxide.

10. The method of claim 1, wherein the surface is formed by a material less than 5 nm thick over copper.

11. The method of claim 1, wherein the third reactant is a boron compound.

12. The method of claim 11, wherein the third reactant is an alkylboron compound.

13. The method of claim 12, wherein the third reactant is triethyl boron (TEB).

14. The method of claim 1, wherein the substrate temperature is between about 225°

C. and about 400°

C.

15. The method of claim 1, wherein the substrate temperature is between about 275°

C. and about 350°

C.

16. The method of claim 1, wherein the substrate temperature is between about 300°

C. and about 325°

C.

17. The method of claim 1, wherein the thin film is a conductive diffusion barrier.

18. The method of claim 17, wherein the diffusion barrier thickness is less than about 20 nm.

19. The method of claim 17, wherein the diffusion barrier thickness is less than about 10 nm.

20. The method of claim 17, wherein the diffusion barrier thickness is less than about 5 nm.

21. A nanolaminate structure produced by the method of claim 1.

22. The nanolaminate structure of claim 21, wherein each layer comprises a different composition from an adjacent layer.

23. The nanolaminate structure of claim 22, wherein two different metal nitrides are alternated.

24. The nanolaminate structure of claim 21 including at least one metal carbide layer.

25. A method of depositing a material on a substrate in a reaction space, the substrate comprising a surface susceptible to halide attack, the method comprising providing alternated pulses of reactants in a plurality of deposition cycles, each cycle comprising:

supplying a first reactant to chemisorb no more than about one monolayer of a halide-terminated species over the surface;

removing excess first reactant and reaction by-product from the reaction space;

supplying a hydrogen-bearing second reactant;

removing excess second reactant and reaction by-product from the reaction space; and

supplying a third reactant that is capable of gettering halides from the substrate surface prior to repeating the cycle.

26. The method of claim 25, wherein the first reactant comprises a metal halide.

27. The method of claim 25, wherein the second reactant comprises a source of nitrogen and the material comprises a transition metal nitride.

28. The method of claim 25, wherein the material comprises a thin film within a nanolaminate stack.

29. The method of claim 25, wherein the third reactant is a carbon source.

30. The method of claim 25, wherein the second reactant is supplied after the first reactant and prior to the third reactant.

31. The method of claim 25, wherein the second reactant is a non-metal species-contributing reactant.

32. A method of forming a WN_xC_y thin film on a substrate within a reaction space by an atomic layer deposition (ALD) type process, wherein the ALD type process comprises providing alternating pulses of reactants in a plurality of deposition cycles, each cycle comprising supplying:

WF₆;

NH₃; and

triethyl boron (TEB), wherein excess reactant and/or reactant byproducts are removed from the reaction space prior to supplying the next reactant and wherein TEB is never the next reactant supplied after WF₆.

33. The method of claim 32, wherein the substrate comprises one or more sensitive surfaces.

34. The method of claim 33, wherein the substrate comprises a copper surface.

35. The method of claim 32, wherein the substrate comprises a dielectric surface.

36. The method of claim 32, wherein the substrate comprises a silicon surface.

37. The method of claim 32, wherein the WN_xC_y thin film is a diffusion barrier.

38. The method of claim 37, wherein the thickness of the diffusion barrier is less than about 5 nm.

39. The method of claim 32, wherein the substrate temperature is between about 300°

C. and about 325°

C.

40. The method of claim 32, wherein the WN_xC_y thin film comprises about 55 at.-% tungsten, about 25 to about 30 at.-% carbon and about 15 to about 20 at.-% nitrogen.

41. A method of forming a metal nitride carbide thin film on a substrate in a reaction space by an atomic layer deposition (ALD) type process, the ALD type process comprising:

supplying a first metal-containing reactant to chemisorb no more than about one monolayer over the surface;

removing excess first reactant and reaction by-product from the reaction space;

supplying a nitrogen-containing second reactant;

removing excess second reactant and reaction by-product from the reaction space;

supplying triethyl boron (TEB); and

removing excess TEB and reaction by-product from the reaction space, wherein the TEB is never the reactant provided immediately after the metal-containing first reactant.

42. The method of claim 41, wherein the metal-containing first reactant is a metal halide.

43. The method of claim 42, wherein the metal-containing first reactant is tungsten hexafluoride (WF₆).

44. The method of claim 41, wherein the metal nitride carbide is WN_xC_y.

45. The method of claim 41, wherein the second reactant is NH₃.

46. A process for producing an integrated circuit comprising:

forming a damascene structure including trenches in an insulating material on a substrate;

placing the substrate in a reaction chamber;

depositing a metal nitride carbide diffusion barrier by an atomic layer deposition (ALD) process;

depositing metal over the metal carbide nitride.

47. The method of claim 46, wherein the ALD process comprises a plurality of cycles, each cycle comprising at least one pulse of a gettering agent.

48. The method of claim 47, wherein the ALD process further comprises providing a pulse of a metal halide, wherein an intervening reactant pulse is always provided between a pulse of a metal halide and a pulse of the gettering agent.

49. The method of claim 48, wherein an intervening reactant pulse comprises a pulse of NH₃.

50. The method of claim 46, wherein exposed copper oxide is reduced prior to depositing the metal nitride carbide diffusion barrier.

51. The method of claim 50, wherein the exposed copper oxide is reduced with a compound selected from the group consisting of alcohols, aldehydes and carboxylic acids.

52. The method of claim 46, additionally including the step of treating the substrate surface with ammonia following reduction of the exposed copper oxide.

53. The method of claim 46, additionally including the steps of depositing a metal oxide on the substrate and reducing the metal oxide to metal, after depositing the metal nitride carbide diffusion barrier and prior to depositing metal over the metal nitride carbide.

54. The method of claim 53, wherein the deposited metal oxide is reduced by exposure to a compound selected from the group consisting of alcohols, aldehydes and carboxylic acids.

55. The method of claim 46, additionally comprising the step of depositing a seed layer prior to depositing metal over the metal nitride carbide.

56. The method of claim 46, wherein the metal nitride carbide is WN_xC_y.

57. The method of claim 46, wherein the metal deposited over the metal nitride carbide is copper.

58. The method of claim 57, wherein the copper is deposited by a method selected from the group consisting of electroless plating, electrochemical deposition, chemical vapor deposition and catalytically enhanced chemical vapor deposition.

59. The method of claim 46, wherein the reaction chamber is part of a cluster tool.