Formation of refractory metal nitrides using chemisorption techniques

• US 20030049931A1
• Filed: 09/19/2001
• Published: 03/13/2003
• Est. Priority Date: 09/19/2001
• Status: Abandoned Application

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Yin, Lin, Srinivas, Ramanujapuram A., Chang, Mei, Mak, Alfred W., Byun, Jeong Soo, Gelatos, Avgerinos, Kori, Moris, Wu, Frederick C., Sinha, Ashok K.
• Application Number:
  US09/960,469
• Publication Number:
  US 20030049931A1
• Time in Patent Office: Days
• US Class Current: 438/649
• CPC Class Codes: H01L 21/28562 Selective deposition
• CPC Class Codes: H01L 21/76843 formed in openings in a dielectric
• CPC Class Codes: H01L 21/76876 for deposition from the gas phase, e.g. CVD

Abstract

Refractory metal nitride layers for integrated circuit fabrication are described. The refractory metal nitride layer may be formed by sequentially chemisorbing alternating monolayers of a nitrogen-containing compound and a refractory metal compound onto a substrate. A composite refractory metal nitride layer is also described. The composite refractory metal nitride layer may be formed by sequentially chemisorbing monolayers of a nitrogen-containing compound and two or more refractory metal compounds onto a substrate.

Claims

1. A method of film deposition, comprising the step of:

(a) chemisorbing monolayers of a nitrogen-containing compound and one or more refractory metal compounds on a substrate to form a refractory metal nitride layer thereon.

2. The method of claim 1 wherein the substrate is subjected to a purge gas following chemisorption of each monolayer.

3. The method of claim 1 wherein the nitrogen-containing compound is selected from the group of ammonia (NH₃), hydrazine (N₂H₄), monomethyl hydrazine (CH₃N₂H₃), dimethyl hydrazine (C₂H₆N₂H₂), t-butylhydrazine (C₄H₉N₂H₃), phenylhydrazine (C₆H₅N₂H₃), 2,2′

-azoisobutane ((CH₃)₆C₂N₂), ethylazide (C₂H₅N₃), as well as combinations thereof.

4. The method of claim 1 wherein the one or more refractory metal compounds comprise a refractory metal selected from the group of titanium (Ti), tungsten (W), vanadium (V), niobium (Nb), tantalum (Ta), zirconium (Zr), hafnium (Hf), chromium (Cr), and molybdenum (Mo).

5. The method of claim 4 wherein the one or more refractory metal compounds are selected from the group of titanium tetrachloride (TiCl₄), tungsten hexafluoride (WF₆), tantalum pentachloride (TaCl₅), zirconium tetrachloride (ZrCl₄), hafnium tetrachloride (HfCl₄), molybdenum pentachloride (MOCl₅), niobium pentachloride (NbCl₅), vanadium pentachloride (VCl₅), chromium tetrachloride (CrCl₄), titanium iodide (Til₄), titanium bromide (TiBr₄), tetrakis(dimethylamido)titanium (TDMAT), pentakis(dimethylamido)tantalum (PDMAT), tetrakis(diethylamido)titanium (TDEAT), tungsten hexacarbonyl (W(CO)₆), tungsten hexachloride (WCl₆), tetrakisdiethylamido)titanium (TDEAT), pentakisdiethylamido)tantalum (PDEAT), and combinations thereof.

6. The method of claim 1 wherein step (a) is performed at a temperature between about 20°

C. and about 600°

C.

7. The method of claim 1 wherein step (a) is performed at a pressure less than about 100 torr.

8. The method of claim 2 wherein the purge gas is selected from the group of helium (He), argon (Ar), hydrogen (H₂), nitrogen (N₂), ammonia (NH₃), and combinations thereof.

9. The method of claim 1 wherein monolayers of the nitrogen-containing compound and the one or more refractory metal compounds are alternately chemisorbed on the substrate.

10. The method of claim 9 wherein one monolayer of the nitrogen-containing compound is chemisorbed on the substrate between each chemisorbed monolayer of the one or more refractory metal compounds.

11. The method of claim 10 wherein the monolayer of the nitrogen-containing compound is chemisorbed on the substrate prior to the one or more refractory compounds.

12. The method of claim 10 wherein one of the one or more refractory metal compounds is chemisorbed on the substrate prior to the nitrogen-containing compound.

13. The method of claim 9 wherein one monolayer of the nitrogen-containing compound is chemisorbed on the substrate after two or more monolayers of the one or more refractory metal compounds are chemisorbed thereon.

14. The method of claim 9 wherein two or more monolayers of the one or more refractory metal compounds are chemisorbed on the substrate after one monolayer of the nitrogen-containing compound is chemisorbed thereon.

15. A method of forming a barrier layer structure for use in integrated circuit fabrication, comprising the steps of:

(a) providing a substrate having an oxide layer thereon, wherein the oxide layer has apertures formed therein to a top surface of the substrate; and

(b) forming at least one refractory metal

nitride layer on at least portions of the substrate surface, wherein the at least one refractory metal nitride layer is formed using a sequential chemisorption process.

16. The method of claim 15 wherein the at least one refractory metal nitride layer comprises one or more refractory metals.

17. The method of claim 16 wherein the one or more refractory metals are selected from the group of titanium (Ti), tungsten (W), vanadium (V), niobium (Nb), tantalum (Ta), zirconium (Zr), hafnium (Hf), chromium (Cr), and molybdenum (Mo).

18. The method of claim 15 wherein the sequential chemisorption process of step (b) comprises the step of:

(c) chemisorbing monolayers of a nitrogen-containing compound and one or more refractory metal compounds on the substrate to form the refractory metal nitride layer thereon.

19. The method of claim 18 wherein the substrate is subjected to a purge gas following chemisorption of each monolayer.

20. The method of claim 18 wherein the nitrogen-containing compound is selected from the group of ammonia (NH₃), hydrazine (N₂H₄), monomethyl hydrazine (CH₃N₂H₃), dimethyl hydrazine (C₂H₆N₂H₂), t-butylhydrazine (C₄H₉N₂H₃), phenylhydrazine (C₆H₅N₂H₃), 2,2′

-azoisobutane ((CH₃)₆C₂N₂), ethylazide (C₂H₅N₃), as well as combinations thereof.

21. The method of claim 18 wherein the one or more refractory metal compounds are selected from the group of titanium tetrachloride (TiCl₄), tungsten hexafluoride (WF₆), tantalum pentachloride (TaCl₅), zirconium tetrachloride (ZrCl₄), hafnium tetrachloride (HfCl₄), molybdenum pentachloride (MoCl₅), niobium pentachloride (NbCl₅), vanadium pentachloride (VCl₅), chromium tetrachloride (CrCl₄), titanium iodide (Til₄), titanium bromide (TiBr₄), tetrakis(dimethylamido)titanium (TDMAT), pentakis(dimethylamido) tantalum (PDMAT), tetrakis(diethylamido)titanium (TDEAT), tungsten hexacarbonyl (W(CO)₆), tungsten hexachloride (WCl₆), tetrakisdiethylamido)titanium (TDEAT), pentakisdiethylamido)tantalum (PDEAT), and combinations thereof.

22. The method of claim 18 wherein step (c) is performed at a temperature between about 20°

C. and about 600°

C.

23. The method of claim 18 wherein step (c) is performed at a pressure less than about 100 torr.

24. The method of claim 19 wherein the purge gas is selected from the group of helium (He), argon (Ar), hydrogen (H₂), nitrogen (N₂), ammonia (NH₃), and combinations thereof.

25. The method of claim 18 wherein monolayers of the nitrogen-containing compound and the one or more refractory metal compounds are alternately chemisorbed on the substrate.

26. The method of claim 25 wherein one monolayer of the nitrogen-containing compound is chemisorbed on the substrate between each chemisorbed monolayer of the one or more refractory metal compounds.

27. The method of claim 26 wherein the nitrogen-containing compound is chemisorbed on the substrate prior to the one or more refractory compounds.

28. The method of claim 26 wherein one monolayer of the one or more refractory metal compounds is chemisorbed on the substrate prior to the monolayer of the nitrogen-containing compound.

29. The method of claim 25 wherein one monolayer of the nitrogen-containing compound is chemisorbed on the substrate after two or more monolayers of the one or more refractory metal compounds are chemisorbed thereon.

30. The method of claim 25 wherein two or more monolayers of the one or more refractory metal compounds are chemisorbed on the substrate after one monolayer of the nitrogen-containing compound is chemisorbed thereon.

31. A method of fabricating a device, comprising:

forming one or more memory cells on a substrate, wherein each memory cell includes two electrodes separated one from the other by a memory cell dielectric material, and wherein at least one of the two electrodes comprises a refractory metal nitride layer formed using a sequential chemisorption process.

32. The method of claim 31 wherein the refractory metal nitride layer comprises one or more refractory metals.

33. The method of claim 31 wherein the one or more refractory metals are selected from the group of titanium (Ti), tungsten (W), vanadium (V), niobium (Nb), tantalum (Ta), zirconium (Zr), hafnium (Hf), chromium (Cr), and molybdenum (Mo).

34. The method of claim 31 wherein the sequential chemisorption process of step (b) comprises the step of:

(c) chemisorbing monolayers of a nitrogen-containing compound and one or more refractory metal compounds on the substrate to form the refractory metal nitride layer thereon.

35. The method of claim 34 wherein the substrate is subjected to a purge gas following chemisorption of each monolayer.

36. The method of claim 34 wherein the nitrogen-containing compound is selected from the group of ammonia (NH₃), hydrazine (N₂H₄), monomethyl hydrazine (CH₃N₂H₃), dimethyl hydrazine (C₂H₆N₂H₂), t-butylhydrazine (C₄H₉N₂H₃), phenylhydrazine (C₆H₅N₂H₃), 2,2′

-azoisobutane ((CH₃)₆C₂N₂), ethylazide (C₂H₅N₃), as well as combinations thereof.

37. The method of claim 34 wherein the one or more refractory metal compounds are selected from the group of titanium tetrachloride (TiCl₄), tungsten hexafluoride (WF₆), tantalum pentachloride (TaCl₅), zirconium tetrachloride (ZrCl₄), hafnium tetrachloride (HfCl₄), molybdenum pentachloride (MoCl₅), niobium pentachloride (NbCl₅), vanadium pentachloride (VCl₅), chromium tetrachloride (CrCl₄), titanium iodide (Til₄), titanium bromide (TiBr₄), tetrakis(dimethylamido)titanium (TDMAT), pentakis(dimethylamido) tantalum (PDMAT), tetrakis(diethylamido)titanium (TDEAT), tungsten hexacarbonyl (W(CO)₆), tungsten hexachloride (WCl₆), tetrakisdiethylamido)titanium (TDEAT), pentakisdiethylamido)tantalum (PDEAT), and combinations thereof.

38. The method of claim 34 wherein step (c) is performed at a temperature between about 20°

C. and about 600°

C.

39. The method of claim 34 wherein step (c) is performed at a pressure less than about 100 torr.

40. The method of claim 35 wherein the purge gas is selected from the group of helium (He), argon (Ar), hydrogen (H₂), nitrogen (N₂), ammonia (NH₃), and combinations thereof.

41. The method of claim 34 wherein monolayers of the nitrogen-containing compound and the one or more refractory metal compounds are alternately chemisorbed on the substrate.

42. The method of claim 41 wherein one monolayer of the nitrogen-containing compound is chemisorbed on the substrate between each chemisorbed monolayer of the one or more refractory metal compounds.

43. The method of claim 41 wherein the nitrogen-containing compound is chemisorbed on the substrate prior to the one or more refractory compounds.

44. The method of claim 41 wherein one monolayer of the one or more refractory metal compounds is chemisorbed on the substrate prior to the monolayer of the nitrogen-containing compound.

45. The method of claim 41 wherein one monolayer of the nitrogen-containing compound is chemisorbed on the substrate after two or more monolayers of the one or more refractory metal compounds are chemisorbed thereon.

46. The method of claim 41 wherein two or more monolayers of the one or more refractory metal compounds are chemisorbed on the substrate after one monolayer of the nitrogen-containing compound is chemisorbed.

47. The method of claim 31 wherein the memory cell dielectric material is an oxide.

48. The method of claim 47 wherein the oxide is tantalum pentoxide (Ta₂O₅).

49. The method of claim 48 wherein the Ta₂O₅ is formed on the substrate by

positioning the substrate in a deposition chamber;

providing a gas mixture to the deposition chamber, wherein the gas mixture comprises a tantalum containing metal organic precursor and an oxidizing gas; and

reacting the gas mixture in the presence of an electric field to form Ta₂O₅ on the substrate.

50. The method of claim 48 wherein the Ta₂O₅ is doped with aluminum oxide (Al₂O₃).

51. The method of claim 49 wherein the gas mixture further comprises an aluminum containing metal organic precursor.

52. A computer storage medium containing a software routine that, when executed, causes a general purpose computer to control a deposition chamber using a method of thin film deposition comprising the step of:

(a) forming a refractory metal nitride layer on a substrate, wherein the refractory metal nitride layer is formed using a sequential chemisorption process.

53. The computer storage medium of claim 52 wherein the at least one refractory metal nitride layer comprises one or more refractory metals.

54. The computer storage medium of claim 53 wherein the one or more refractory metals are selected from the group of titanium (Ti), tungsten (W), vanadium (V), niobium (Nb), tantalum (Ta), zirconium (Zr), hafnium (Hf), chromium (Cr), and molybdenum (Mo).

55. The computer storage medium of claim 52 wherein the sequential chemisorption process of step (a) comprises the step of:

(b) chemisorbing monolayers of a nitrogen-containing compound and one or more refractory metal compounds on the substrate to form the refractory metal nitride layer thereon.

56. The computer storage medium of claim 55 wherein the substrate is subjected to a purge gas following chemisorption of each monolayer.

57. The computer storage medium of claim 55 wherein the nitrogen-containing compound is selected from the group of ammonia (NH₃), hydrazine (N₂H₄), monomethyl hydrazine (CH₃N₂H₃), dimethyl hydrazine (C₂H₆N₂H₂), t-butylhydrazine (C₄H₉N₂H₃), phenylhydrazine (C₆H₅N₂H₃), 2,2′

-azoisobutane ((CH₃)₆C₂N₂), ethylazide (C₂H₅N₃), as well as combinations thereof.

58. The computer storage medium of claim 55 wherein the one or more refractory metal compounds are selected from the group of titanium tetrachloride (TiCl₄), tungsten hexafluoride (WF₆), tantalum pentachloride (TaCl₅), zirconium tetrachloride (ZrCl₄), hafnium tetrachloride (HfCl₄), molybdenum pentachloride (MoCl₅), niobium pentachloride (NbCl₅), vanadium pentachloride (VCl₅), chromium tetrachloride (CrCl₄), titanium iodide (Til₄), titanium bromide (TiBr₄), tetrakis(dimethylamido)titanium (TDMAT), pentakis(dimethylamido) tantalum (PDMAT), tetrakis(diethylamido)titanium (TDEAT), tungsten hexacarbonyl (W(CO)₆), tungsten hexachloride (WCl₆), tetrakisdiethylamido)titanium (TDEAT), pentakisdiethylamido)tantalum (PDEAT), and combinations thereof.

59. The computer storage medium of claim 55 wherein step (b) is performed at a temperature between about 20°

C. and about 600°

C.

60. The computer storage medium of claim 55 wherein step (b) is performed at a pressure less than about 100 torr.

61. The computer storage medium of claim 56 wherein the purge gas is selected from the group of helium (He), argon (Ar), hydrogen (H₂), nitrogen (N₂), ammonia (NH₃), and combinations thereof.

62. The computer storage medium of claim 55 wherein monolayers of the nitrogen-containing compound and the one or more refractory metal compounds are alternately chemisorbed on the substrate.

63. The computer storage medium of claim 62 wherein one monolayer of the nitrogen-containing compound is chemisorbed on the substrate between each chemisorbed monolayer of the one or more refractory metal compounds.

64. The computer storage medium of claim 62 wherein the nitrogen-containing compound is chemisorbed on the substrate prior to the one or more refractory metal compounds.

65. The computer storage medium of claim 62 wherein one of the one or more refractory metal compounds is chemisorbed on the substrate prior to the nitrogen-containing compound.

66. The computer storage medium of claim 62 wherein one monolayer of the nitrogen-containing compound is chemisorbed on the substrate after two or more monolayers of the one or more refractory metal compounds are chemisorbed thereon.

67. The computer storage medium of claim 62 wherein two or more monolayers of the one or more refractory metal compounds are chemisorbed on the substrate after one monolayer of the nitrogen-containing compound is chemisorbed thereon.

68. A device comprising:

at least one refractory metal nitride layer formed on a substrate, wherein one of the at least one refractory metal nitride layers comprises two or more refractory metals.

69. The device of claim 68 wherein the two or more refractory metals are selected from the group of titanium (Ti), tungsten (W), vanadium (V), niobium (Nb), tantalum (Ta), zirconium (Zr), hafnium (Hf), chromium (Cr), and molybdenum (Mo).

70. A device comprising:

a substrate having an oxide layer thereon, wherein the oxide layer has an aperture formed therein to a top surface of the substrate; and

at least one refractory metal nitride layer formed on portions of the oxide layer and the substrate surface, wherein one of the at least one refractory metal nitride layers comprises two or more refractory metals.

71. The device of claim 70 wherein the two or more refractory metals are selected from the group of titanium (Ti), tungsten (W), vanadium (V), niobium (Ni), tantalum (Ta), zirconium (Zr), hafnium (Hf), chromium (Cr), and molybdenum (Mo).

72. An interconnect structure, comprising:

a substrate having an oxide layer thereon, wherein the oxide layer has apertures formed therein to a top surface of the substrate;

a first refractory metal nitride layer formed on portions of the oxide layer and the substrate surface, wherein the first refractory metal nitride layer comprises one or more refractory metals; and

a second refractory metal nitride layer formed on the first refractory metal nitride layer, wherein the second refractory metal nitride layer comprises one or more refractory metals.

73. The interconnect structure of claim 72 wherein the one or more refractory metals are selected from the group of titanium (Ti), tungsten (W), vanadium (V), niobium (Nb), tantalum (Ta), zirconium (Zr), hafnium (Hf), chromium (Cr), and molybdenum (Mo).

74. The interconnect structure of claim 72 wherein the first refractory metal nitride layer has a thickness less than about 100 Å

(Angstroms).

75. The interconnect structure of claim 72 wherein the second refractory metal nitride layer has a thickness in a range of about 100 Å

to about 1000 Å

.

76. A memory cell device, comprising:

one or more memory cells on a substrate, wherein each memory cell includes two electrodes separated one from the other by a memory cell dielectric material, and wherein at least one of the two electrodes is a refractory metal nitride layer comprised of two or more refractory metals.

77. The device of claim 76 wherein the two or more refractory metals are selected from the group of titanium (Ti), tungsten (W), vanadium (V), niobium (Ni), tantalum (Ta), zirconium (Zr), hafnium (Hf), chromium (Cr), and molybdenum (Mo).