Plasma treatment of hafnium-containing materials

• US 20060019033A1
• Filed: 06/24/2005
• Published: 01/26/2006
• Est. Priority Date: 05/21/2004
• Status: Abandoned Application

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Ma, Yi, Goyani, Tejal, Ahmed, Khaled Z., Kher, Shreyas S., Narwankar, Pravin K., Muthukrishnan, Shankar, Sharangpani, Rahul
• Application Number:
  US11/167,070
• Publication Number:
  US 20060019033A1
• Time in Patent Office: Days
• US Class Current: 427/248.100
• CPC Class Codes: C23C 16/401 containing silicon
• CPC Class Codes: C23C 16/405 of refractory metals or yttrium
• CPC Class Codes: C23C 16/4488 by in situ generation of reactive gas by chemical or electrochemical reaction
• CPC Class Codes: C23C 16/45525 Atomic layer deposition [ALD]
• CPC Class Codes: C23C 16/45529 specially adapted for making a layer stack of alternating different compositions or gradient compositions
• CPC Class Codes: C23C 16/56 After-treatment
• CPC Class Codes: H01L 21/02175 characterised by the metal H01L21/02197 takes precedence
• CPC Class Codes: H01L 21/02181 the material containing hafnium, e.g. HfO2
• CPC Class Codes: H01L 21/02183 the material containing tantalum, e.g. Ta2O5
• CPC Class Codes: H01L 21/02189 the material containing zirconium, e.g. ZrO2
• CPC Class Codes: H01L 21/022 the layer being a laminate, i.e. composed of sublayers, e.g. stacks of alternating high-k metal oxides adhesion layers or buffer layers H01L21/02304, H01L21/02362
• 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 21/0234 treatment by exposure to a plasma
• CPC Class Codes: H01L 21/3141 Deposition using atomic layer deposition techniques [ALD]
• CPC Class Codes: H01L 21/3143 composed of alternated layers or of mixtures of nitrides and oxides or of oxinitrides, e.g. formation of oxinitride by oxidation of nitride layers
• CPC Class Codes: H01L 21/31637 Deposition of Tantalum oxides, e.g. Ta2O5
• CPC Class Codes: H01L 21/31645 Deposition of Hafnium oxides, e.g. HfO2

Abstract

In one embodiment, a method for forming a dielectric material is provided which includes exposing a substrate sequentially to a metal-containing precursor and an oxidizing gas to form metal oxide (e.g., HfO_x) during an ALD process and subsequently exposing the substrate to an inert plasma process and a thermal annealing process. Generally, the metal oxide contains hafnium, tantalum, titanium, aluminum, zirconium, lanthanum or combinations thereof. In one example, the inert plasma process contains argon and is free of nitrogen, while the thermal annealing process contains oxygen. In another example, an ALD process to form a metal oxide includes exposing the substrate sequentially to a metal precursor and an oxidizing gas containing water vapor formed by a catalytic water vapor generator. In an alternative embodiment, a method for forming a dielectric material is provide which includes exposing a substrate to a deposition process to form a metal oxide layer and subsequently exposing the substrate to a nitridation plasma process and a thermal annealing process to form metal oxynitride (e.g., HfO_xN_y).

Claims

1. A method for forming a dielectric material on a substrate, comprising:

exposing a substrate sequentially to a metal-containing precursor and an oxidizing gas during an ALD process to form a metal oxide material thereon;

exposing the substrate to an inert plasma process; and

exposing the substrate to a thermal annealing process.

2. The method of claim 1, wherein the inert plasma process comprises an inert gas selected from the group consisting of argon, helium, neon and combinations thereof.

3. The method of claim 2, wherein the inert plasma process occurs for a time period within a range from about 30 seconds to about 5 minutes and at a power output within a range from about 500 watts to about 3,000 watts.

4. The method of claim 3, wherein the time period is within a range from about 1 minute to about 3 minutes and the power output is within a range from about 900 watts to about 1,800 watts.

5. The method of claim 2, wherein the inert plasma process comprises argon and is free of nitrogen or substantially free of nitrogen.

6. The method of claim 5, wherein the thermal annealing process occurs for a time period within a range from about 1 second to about 120 seconds and at a temperature within a range from about 600°

C. to about 1,200°

C.

7. The method of claim 6, wherein the time period is within a range from about 5 seconds to about 30 seconds and the temperature is within a range from about 800°

C. to about 1,100°

C.

8. The method of claim 6, wherein the thermal annealing process further comprises oxygen.

9. The method of claim 5, wherein the metal oxide material comprises at least one element selected from the group consisting of hafnium, tantalum, titanium, aluminum, zirconium, lanthanum and combinations thereof.

10. The method of claim 9, wherein the metal oxide material has a thickness within a range from about 5 Å

to about 100 Å

.

11. The method of claim 10, wherein the metal oxide material comprises hafnium oxide and the thickness is within a range from about 10 Å

to about 60 Å

.

12. The method of claim 10, wherein the metal oxide material has a capacitance of at least about 2.4 μ

F/cm².

13. The method of claim 9, wherein prior to forming the dielectric material, the substrate is exposed to a wet clean process to form an oxide layer with a thickness of about 10 Å

or less.

14. The method of claim 13, wherein the substrate is exposed to a post deposition annealing process after the ALD process and prior to the inert plasma process.

15. A method for forming a dielectric material on a substrate, comprising:

positioning a substrate within a process chamber;

flowing a hydrogen source gas and an oxygen source gas into a water vapor generator to form an oxidizing gas comprising water vapor;

exposing the substrate sequentially to the oxidizing gas and at least one metal-containing precursor during an ALD process to form a dielectric material thereon;

exposing the substrate to an inert plasma process; and

exposing the substrate to a thermal annealing process.

16. The method of claim 15, wherein the at least one metal-containing precursor is selected from the group consisting of a hafnium precursor, a zirconium precursor, an aluminum precursor, a tantalum precursor, a titanium precursor, a lanthanum precursor and combinations thereof.

17. The method of claim 16, wherein the dielectric material comprises at least one material selected from the group consisting of hafnium oxide, zirconium oxide, lanthanum oxide, tantalum oxide, titanium oxide, aluminum oxide, derivatives thereof and combinations thereof.

18. The method of claim 17, wherein prior to forming the dielectric material, the substrate is exposed to a wet clean process to form an oxide layer with a thickness of about 10 Å

or less.

19. The method of claim 15, wherein the inert plasma process comprises argon and is free of nitrogen or substantially free of nitrogen.

20. The method of claim 19, wherein the inert plasma process occurs for a time period within a range from about 1 minute to about 3 minutes and at a power output within a range from about 900 watts to about 1,800 watts.

21. The method of claim 19, wherein the thermal annealing process occurs for a time period within a range from about 5 seconds to about 30 seconds and at a temperature within a range from about 800°

C. to about 1,100°

C.

22. The method of claim 21, wherein the thermal annealing process further comprises oxygen.

23. The method of claim 17, wherein the dielectric material has a thickness within a range from about 5 Å

to about 100 Å

.

24. The method of claim 23, wherein the dielectric material comprises hafnium oxide and the thickness is within a range from about 10 Å

to about 60 Å

.

25. The method of claim 23, wherein the substrate is exposed to a post deposition annealing process after the ALD process and prior to the inert plasma process.

26. The method of claim 23, wherein the hafnium-containing material has a capacitance of at least about 2.4 μ

F/cm².

27. A method for forming a hafnium-containing material on a substrate, comprising:

exposing a substrate to a deposition process to form a dielectric material containing hafnium oxide thereon;

exposing the substrate to an inert plasma process that comprises argon and is free of nitrogen or substantially free of nitrogen; and

exposing the substrate to a thermal annealing process comprising oxygen.

28. The method of claim 27, wherein the hafnium-containing material has a capacitance of at least about 2.4 μ

F/cm².

29. The method of claim 27, wherein the deposition process to form the dielectric material is an ALD process comprising exposing the substrate sequentially to an oxidizing gas and a hafnium precursor to form the dielectric material containing hafnium oxide, wherein the oxidizing gas comprises water vapor and is formed by flowing a hydrogen source gas and an oxygen source gas into a water vapor generator.

30. A method for forming a dielectric material on a substrate, comprising:

exposing a substrate to a deposition process to form a metal oxide layer thereon;

exposing the substrate to a nitridation plasma process to form a metal oxynitride layer thereon; and

exposing the substrate to a thermal annealing process to form a dielectric material.

31. The method of claim 30, wherein the nitridation plasma process occurs for a time period within a range from about 1 minute to about 3 minutes and at a power output within a range from about 900 watts to about 1,800 watts.

32. The method of claim 31, wherein the nitridation plasma process comprises a process gas containing a nitrogen concentration of about 50 vol % or less.

33. The method of claim 32, wherein the dielectric material has a nitrogen concentration in a range from about 5 at % to about 25 at %.

34. The method of claim 33, wherein the metal oxide layer is substantially free of silicon.

35. The method of claim 30, wherein the metal oxide layer comprises at least one element selected from the group consisting of hafnium, tantalum, titanium, aluminum, zirconium, lanthanum and combinations thereof.

36. The method of claim 35, wherein the thermal annealing process occurs for a time period within a range from about 5 seconds to about 30 seconds and at a temperature within a range from about 800°

C. to about 1,100°

C.

37. The method of claim 36, wherein the thermal annealing process further comprises oxygen.

38. The method of claim 30, wherein the dielectric material has a thickness within a range from about 5 Å

to about 100 Å

.

39. The method of claim 38, wherein the dielectric material comprises hafnium oxynitride and the thickness is within a range from about 10 Å

to about 60 Å

.

40. The method of claim 39, wherein the dielectric material has a capacitance of at least about 2.4 μ

F/cm².

41. The method of claim 30, wherein the deposition process to form the metal oxide layer is an ALD process.

42. The method of claim 41, wherein prior to the ALD process, the substrate is exposed to a wet clean process to form an oxide layer with a thickness of about 10 Å

or less.

43. The method of claim 42, wherein the substrate is exposed to a post deposition annealing process after the ALD process and prior to the nitridation plasma process.

44. The method of claim 41, wherein the ALD process comprises exposing the substrate sequentially to an oxidizing gas and at least one metal-containing precursor to form the metal oxide layer thereon.

45. The method of claim 44, wherein the oxidizing gas comprises water vapor and is formed by flowing a hydrogen source gas and an oxygen source gas into a water vapor generator.

46. The method of claim 45, wherein the at least one metal-containing precursor is selected from the group consisting of a hafnium precursor, a zirconium precursor, an aluminum precursor, a tantalum precursor, a titanium precursor, a lanthanum precursor and combinations thereof.

47. A method for forming a hafnium-containing material on a substrate, comprising:

exposing a substrate to a deposition process to form a dielectric material containing hafnium oxide thereon;

exposing the substrate to a nitridation plasma process to form hafnium oxynitride from the hafnium oxide; and

exposing the substrate to a thermal annealing process comprising oxygen.

48. The method of claim 47, wherein the hafnium-containing material has a capacitance of at least about 2.4 μ

F/cm².

49. The method of claim 47, wherein the deposition process to form the dielectric material is an ALD process comprising exposing the substrate sequentially to an oxidizing gas and a hafnium precursor to form the dielectric material containing hafnium oxide, wherein the oxidizing gas comprises water vapor and is formed by flowing a hydrogen source gas and an oxygen source gas into a water vapor generator.