Vapor deposition of metal carbide films

• US 7,611,751 B2
• Filed: 11/01/2006
• Issued: 11/03/2009
• Est. Priority Date: 11/01/2006
• Status: Active Grant

• Current Assignee: ASM IP Holding B.V. (ASM International NV)
• Original Assignee: ASM America Incorporated (ASM International NV)
• Inventors: Elers, Kai-Erik
• Primary Examiner(s): CULBERT, ROBERTS P
• Application Number:
  US11/591,845
• Publication Number:
  US 20080102204A1
• Time in Patent Office: 1,098 Days
• Field of Search: 427/569, 427/249.1
• US Class Current: 427/249.1
• CPC Class Codes: C23C 16/32 Carbides
• CPC Class Codes: C23C 16/45527 characterized by the ALD cycle, e.g. different flows or temperatures during half-reactions, unusual pulsing sequence, use of precursor mixtures or auxiliary reactants or activations
• 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: C23C 16/45542 Plasma being used non-continuously during the ALD reactions

Abstract

Methods of forming metal carbide thin films are provided. According to preferred embodiments, metal carbide thin films are formed in an atomic layer deposition (ALD) process by alternately and sequentially contacting a substrate in a reaction space with spatially and temporally separated vapor phase pulses of a metal source chemical, a reducing agent and a carbon source chemical. The reducing agent is preferably selected from the group consisting of excited species of hydrogen and silicon-containing compounds.

Claims

1. An atomic layer deposition (ALD) process for growing a metal carbide film over a substrate in a reaction space, comprising alternately and sequentially contacting the substrate with spatially and temporally separated vapor phase pulses of a metal source chemical, a reducing agent and a carbon-containing compound.

2. The process of claim 1, further comprising removing excess metal source chemical, reducing agent or carbon-containing compound after each of said pulses.

3. The process of claim 2, wherein removing comprises purging the reaction space with an inert gas.

4. The process of claim 2, wherein removing comprises evacuating the reaction space using a vacuum generated by a pumping system.

5. The process of claim 1, wherein the reducing agent is a silicon-containing compound selected from the group consisting of silane (SiH₄), disilane (Si₂H₆) and trisilane (Si₃H₈).

6. The process of claim 1, wherein the reducing agent is a boron-containing compound selected from the group consisting of borane (BH₃) and diborane (B₂H₆).

7. The process of claim 1, wherein the reducing agent comprises excited species of hydrogen (H₂).

8. The process of claim 6, wherein the excited species of hydrogen are generated in the reaction space.

9. The process of claim 6, wherein the excited species of hydrogen are generated remotely.

10. The process of claim 1, wherein the metal carbide film comprises one or more metals selected from the group consisting of titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), manganese (Mn), rhenium (Re), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), silver (Ag), gold (Au), palladium (Pd), platinum (Pt), rhodium (Rh), iridium (Ir), ruthenium (Ru), osmium (Os) and aluminum (Al).

11. The process of claim 1, wherein the metal source chemical comprises at least one ligand.

12. The process of claim 11, wherein the ligand comprises organic species selected from the group consisting of dialkylamido compounds, cyclopentadienyl compounds, alkoxide compounds, alkyl compounds, carbonyl, cyclo-octadiene, benzene and hydrogand.

13. The process of claim 11, wherein the ligand comprises a halogen selected from the group consisting of bromine (Br), chlorine (Cl), fluorine (F) and iodine (I).

14. The process of claim 13, wherein the metal source chemical is selected from the group consisting of TiCl₄, ZrCl₄, HfCl₄, VCl₅, NbCl₅, TaCl₅, TaF₅, CrCl₄, WCl₅, WCl₆, WF₆, and AlCl₃.

15. The process of claim 1, wherein the carbon-containing compound is a hydrocarbon.

16. The process of claim 15, wherein the hydrocarbon is selected from the group consisting of alkanes, alkenes and alkynes.

17. The process of claim 16, wherein the hydrocarbon is acetylene (C₂H₂).

18. The process of claim 1, wherein the carbon-containing compound comprises boron.

19. The process of claim 18, wherein the carbon-containing compound is triethyl boron (B(CH₂CH₃)3).

20. The process of claim 1, wherein the reducing agent is provided at intervals during the ALD process.

21. An atomic layer deposition (ALD) process for growing a metal carbide thin film on a substrate in a reaction space, comprising the sequential steps of:

a) contacting the substrate with a vapor phase pulse of a metal source chemical;

b) removing excess metal source chemical from the reaction space;

c) contacting the substrate with a vapor phase pulse of a reducing agent;

d) removing excess reducing agent from the reaction space;

e) contacting the substrate with a vapor phase pulse of a carbon-containing compound; and

f) removing any excess carbon-containing compound from the reaction space.

22. The process of claim 21, further comprising repeating steps a) through f) until a metal carbide film of predetermined thickness is formed over the substrate.

23. The process of claim 21, wherein steps a) through d) are repeated a predetermined number of times before steps e) and f).

24. The process of claim 21, wherein the metal carbide film comprises one or more metals selected from the group consisting of titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), manganese (Mn), rhenium (Re), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), silver (Ag), gold (Au), palladium (Pd), platinum (Pt), rhodium (Rh), iridium (Ir), ruthenium (Ru), osmium (Os) and aluminum (Al).

25. The process of claim 21, wherein the metal source chemical is selected from the group consisting of metal halides and metal organic compounds.

26. The process of claim 25, wherein the metal source chemical is selected from the group consisting of TiCl₄, ZrCl₄, HfCl₄, VCl₅, NbCl₅, TaCl₅, TaF₅, CrCl₄, WCl₅, WCl₆, WF₆, and AlCl₃.

27. The process of claim 25, wherein metal organic compounds are selected from the group consisting of metal dialkylamido compounds and metal cyclopentadienyl compounds.

28. The process of claim 21, further comprising removing any reaction byproducts from the reaction space after each of said pulses.

29. The process of claim 21, wherein contacting comprises feeding said pulses with a carrier gas.

30. The process of claim 21, wherein the reducing agent comprises one or more silicon-containing compounds selected from the group consisting of silane (SiH₄), disilane (Si₂H₆) and trisilane (Si₃H₈).

31. The process of claim 21, wherein the reducing agent comprises one or more boron-containing compounds selected from the group consisting of borane (BH₃) and diborane (B₂H₆).

32. The process of claim 21, wherein the reducing agent comprises excited species of hydrogen (H₂).

33. The process of claim 21, wherein the carbon-containing compound is a hydrocarbon.

34. The process of claim 33, wherein the hydrocarbon is selected from the group consisting of alkanes, alkenes and alkynes.

35. The process of claim 21, wherein the carbon-containing compound comprises boron.

36. The process of claim 35, wherein the carbon-containing compound is triethyl boron (B(CH₂CH₃)3).

37. An atomic layer deposition (ALD) process for growing a metal carbide thin film on a substrate in a reaction space, comprising the sequential steps of:

a) contacting the substrate with a vapor phase pulse of a metal source chemical;

b) contacting the substrate with a vapor phase pulse of a reducing agent; and

c) contacting the substrate with a vapor phase pulse of a carbon-containing compound.

38. The process of claim 37, further comprising repeating steps a) through c) until a metal carbide film of predetermined thickness is formed over the substrate.

39. The process of claim 37, further comprising removing excess reactants and reaction by-products after each of the vapor phase pulses.

40. The process of claim 37, wherein steps a) and b) are repeated a predetermined number of times before step c).

41. The process of claim 37, wherein the metal carbide film comprises one or more metals selected from the group consisting of titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), manganese (Mn), rhenium (Re), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), silver (Ag), gold (Au), palladium (Pd), platinum (Pt), rhodium (Rh), iridium (Ir), ruthenium (Ru), osmium (Os) and aluminum (Al).

42. The process of claim 37, wherein the metal source chemical is selected from the group consisting of metal halides and metal organic compounds.

43. The process of claim 42, wherein the metal source chemical is selected from the group consisting of TiCl₄, ZrCl₄, HfCl₄, VCl₅, NbCl₅, TaCl₅, TaF₅, CrCl₄, WCl₅, WCl₆, WF₆, and AlCl₃.

44. The process of claim 42, wherein metal organic compounds are selected from the group consisting of metal dialkylamido compounds and metal cyclopentadienyl compounds.

45. The process of claim 37, further comprising removing any reaction byproducts from the reaction space after each of said pulses.

46. The process of claim 37, wherein contacting comprises feeding said pulses with a carrier gas.

47. The process of claim 37, wherein the reducing agent comprises silicon-containing compounds selected from the group consisting of silane (SiH₄), disilane (Si₂H₆) and trisilane (Si₃H₈).

48. The process of claim 37, wherein the reducing agent comprises boron-containing compounds selected from the group consisting of borane (BH₃) and diborane (B₂H₆).

49. The process of claim 37, wherein the reducing agent comprises excited species of hydrogen (H₂).

50. The process of claim 37, wherein the carbon-containing compound is a hydrocarbon.

51. The process of claim 50, wherein the hydrocarbon is selected from the group consisting of alkanes, alkenes and alkynes.

52. The process of claim 37, wherein the carbon-containing compound comprises boron.

53. The process of claim 52, wherein the carbon-containing compound is triethyl boron (B(CH₂CH₃)3).

54. A plasma-enhanced atomic layer deposition (PEALD) process for growing a metal carbide thin film on a substrate, comprising alternately and sequentially contacting a substrate in a reaction space with temporally and spatially separated vapor phase pulses of:

a metal source material that forms no more than about one monolayer of a metal thin film on an exposed surface of the substrate;

excited species of hydrogen (H₂) that reduce the metal thin film to an elemental metal thin film; and

a carbon source material that forms no more than about one monolayer of a metal carbide thin film,

wherein any excess metal source material, excited species of hydrogen and carbon source material are removed from the reaction space after each of said pulses.

55. The process of claim 54, wherein the metal carbide thin film comprises one or more metals selected from the group consisting of titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), manganese (Mn), rhenium (Re), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), silver (Ag), gold (Au), palladium (Pd), platinum (Pt), rhodium (Rh), iridium (Ir), ruthenium (Ru), osmium (Os) and aluminum (Al).

56. The process of claim 54, wherein the metal source material is selected from the group consisting of metal halides and metal organic compounds.

57. The process of claim 56, wherein the metal source material is selected from the group consisting of TiCl₄, ZrCl₄, HfCl₄, VCl₅, NbCI₅, TaCl₅, TaF₅, CrCl₄, WCl₅, WCl₆, WF₆, and AlCl₃.

58. The process of claim 54, wherein the metal organic compounds are selected from the group consisting of metal dialkylamido compounds and metal cyclopentadienyl compounds.

59. The process of claim 54, further comprising removing any reaction byproducts from the reaction space after each of said pulses.

60. The process of claim 54, wherein the carbon source material is a hydrocarbon.

61. The process of claim 60, wherein the hydrocarbon is selected from the group consisting of alkanes, alkenes and alkynes.

62. The process of claim 54, wherein the carbon source material comprises boron.

63. The process of claim 62, wherein the carbon source material is triethyl boron (B(CH₂CH₃)3).

64. The process of claim 54, wherein the excited species of hydrogen are generated in the reaction space.

65. The process of claim 54, wherein the excited species of hydrogen are generated in a remote plasma generator.