Deposition of tungsten films for dynamic random access memory (DRAM) applications

• US 20030157760A1
• Filed: 02/20/2002
• Published: 08/21/2003
• Est. Priority Date: 02/20/2002
• Status: Abandoned Application

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Yoon, Hyungsuk A., Hong, Soonil, Zhang, Hui, Xi, Ming, Yang, Michael X.
• Application Number:
  US10/082,048
• Publication Number:
  US 20030157760A1
• Time in Patent Office: Days
• US Class Current: 438/200
• CPC Class Codes: C23C 16/06 characterised by the deposition of metallic material
• CPC Class Codes: C23C 16/45525 Atomic layer deposition [ALD]
• CPC Class Codes: H01L 21/02263 deposition from the gas or vapour phase
• CPC Class Codes: H01L 21/31604 Deposition from a gas or vapour H01L21/31691, H01L21/31695 take precedence
• CPC Class Codes: H01L 28/55 with a dielectric comprising a perovskite structure material
• CPC Class Codes: H01L 28/60 Electrodes
• CPC Class Codes: H01L 28/84 being a rough surface, e.g. using hemispherical grains
• CPC Class Codes: H01L 28/90 having vertical extensions
• CPC Class Codes: H10B 12/038 the capacitor being in a trench in the substrate

Abstract

A method of tungsten deposition for dynamic random access memory (DRAM) applications is described. The DRAM devices typically include two electrodes separated by a dielectric material. At least one of the two electrodes comprises a tungsten-based material. The tungsten-based material may be formed using a cyclical deposition technique. Using the cyclical deposition technique, the tungsten-based material is formed by alternately adsorbing a tungsten-containing precursor and a reducing gas on a structure.

Claims

1. A method of forming an electrode for a capacitor structure, comprising:

providing a substrate structure, wherein the substrate structure comprises an insulating material layer formed over a first electrode;

depositing a tungsten-based layer on the insulating material layer using a cyclical deposition process, wherein the tungsten-based layer comprises a second electrode.

2. The method of claim 1 wherein the cyclical deposition process comprises alternately adsorbing monolayers of a tungsten-containing precursor and a reducing gas on the insulating material layer.

3. The method of claim 1 wherein the tungsten-based layer comprises a material selected from the group consisting of tungsten (W), tungsten boride (W₂B) and tungsten nitride (WN).

4. The method of claim 2 wherein the tungsten-containing precursor is selected from the group consisting of tungsten hexafluoride (WF₆) and tungsten carbonyl (W(CO)₆).

5. The method of claim 2 wherein the reducing gas is selected from the group consisting of ammonia (NH₃), hydrazine (N₂H₄), monomethyl hydrazine (CH₃N₂H₃), dimethyl hydrazine (C₂H₆N₂H₂), t-butyl hydrazine (C₄H₉N₂H₃), phenyl hydrazine (C₆H₅N₂H₃), 2,2′

-azoisobutane ((CH₃)₆C₂N₂), ethylazide (C₂H₅N₃), silane (SiH₄), disilane (Si₂H₆), dichlorosilane (SiCl₂H₂), borane (BH₃), diborane (B₂H₆), triborane (B₃H₉), tetraborane (B₄H₁₂), pentaborane (B₅H₁₅), hexaborane (B₆H₁₈), heptaborane (B₇H₂₁), octaborane (B₈H₂₄), nanoborane (B₉H₂₇) and decaborane (B₁₀H₃₀), and combinations thereof.

6. The method of claim 1 wherein the substrate structure is a trench structure.

7. The method of claim 1 wherein the substrate structure is a crown structure.

8. The method of claim 1 wherein the insulating material comprises a material selected from the group consisting of tantalum pentoxide (Ta₂O₅), silicon oxide/silicon nitride/oxynitride (ONO), aluminum oxide (Al₂O₃), barium strontium titanate (BST), barium titanate, lead zirconate titanate (PZT), lead lanthanium titanate, strontium titanate and strontium bismuth titanate.

9. The method of claim 1 wherein the first electrode comprises polysilicon.

10. The method of claim 1 wherein the first electrode comprises a tungsten-based layer formed using a cyclical deposition process.

11. A method of forming a capacitor structure, comprising:

forming a first electrode on a substrate;

forming an insulating material layer over the first electrode; and

depositing a tungsten-based layer on the insulating material layer using a cyclical deposition process, wherein the tungsten-based layer comprises a second electrode.

12. The method of claim 11 wherein the cyclical deposition process comprises alternately adsorbing monolayers of a tungsten-containing precursor and a reducing gas on the insulating material layer.

13. The method of claim 11 wherein the tungsten-based layer comprises a material selected from the group consisting of tungsten (W), tungsten boride (W₂B) and tungsten nitride (WN).

14. The method of claim 12 wherein the tungsten-containing precursor is selected from the group consisting of tungsten hexafluoride (WF₆) and tungsten carbonyl (W(CO)₆).

15. The method of claims 12 wherein the reducing gas is selected from the group consisting of ammonia (NH₃), hydrazine (N₂H₄), monomethyl hydrazine (CH₃N₂H₃), dimethyl hydrazine (C₂H₆N₂H₂), t-butyl hydrazine (C₄H₉N₂H₃), phenyl hydrazine (C₆H₅N₂H₃), 2,2′

-azoisobutane ((CH₃)₆C₂N₂), ethylazide (C₂H₅N₃), silane (SiH₄), disilane (Si₂H₆), dichlorosilane (SiCl₂H₂), borane (BH₃), diborane (B₂H₆), triborane (B₃H₉), tetraborane (B₄H₁₂), pentaborane (B₅H₁₅), hexaborane (B₆H₁₈), heptaborane (B₇H₂₁), octaborane (B₈H₂₄), nanoborane (B₉H₂₇) and decaborane (B₁₀H₃₀), and combinations thereof.

16. The method of claim 11 wherein the capacitor structure is a trench structure.

17. The method of claim 11 wherein the capacitor structure is a crown structure.

18. The method of claim 11 wherein the insulating material comprises a material selected from the group consisting of tantalum pentoxide (Ta₂O₅), silicon oxide/silicon nitride/oxynitride (ONO), aluminum oxide (Al₂O₃), barium strontium titanate (BST), barium titanate, lead zirconate titanate (PZT), lead lanthanium titanate, strontium titanate and strontium bismuth titanate.

19. The method of claim 11 wherein the first electrode comprises polysilicon.

20. The method of claim 11 wherein the first electrode comprises a tungsten-based layer formed using a cyclical deposition process.

21. A method of forming an electrode, comprising:

providing a substrate to a process chamber; and

depositing a tungsten-based layer on the substrate using a cyclical deposition process comprising a plurality of cycles, wherein each cycle comprises establishing a flow of an inert gas to the process chamber and modulating the flow of the inert gas with an alternating period of exposure to one of either a tungsten-containing precursor and a reducing gas.

22. The method of claim 21 wherein the period of exposure to the tungsten-containing precursor, the period of exposure to the reducing gas, a period of flow of the inert gas between the period of exposure to the tungsten-containing precursor and the period of exposure to the reducing gas, and a period of flow of the inert gas between the period of exposure to the reducing gas and the period of exposure to the tungsten-containing precursor each have the same duration.

23. The method of claim 21 wherein at least one of the period of exposure to the tungsten-containing precursor, the period of exposure to the reducing gas, a period of flow of the inert gas between the period of exposure to the tungsten-containing precursor and the period of exposure to the reducing gas, and a period of flow of the inert gas between the period of exposure to the reducing gas and the period of exposure to the tungsten-containing precursor has a different duration.

24. The method of claim 21 wherein the period of exposure to the tungsten-containing precursor during each deposition cycle of the cyclical deposition process has the same duration.

25. The method of claim 21 wherein at least one period of exposure to the tungsten-containing precursor for one or more deposition cycle of the cyclical deposition process has a different duration.

26. The method of claim 21 wherein the period of exposure to the reducing gas during each deposition cycle of the cyclical deposition process has the same duration.

27. The method of claim 21 wherein at least one period of exposure to the reducing gas for one or more deposition cycle of the cyclical deposition process has a different duration.

28. The method of claim 21 wherein a period of flow of the inert gas between the period of exposure to the tungsten-containing precursor and the period of exposure to the reducing gas during each deposition cycle of the cyclical deposition process has the same duration.

29. The method of claim 21 wherein at least one period of flow of the inert gas between the period of exposure to the tungsten-containing precursor and the period of exposure to the reducing gas for one or more deposition cycle of the cyclical deposition process has a different duration.

30. The method of claim 21 wherein a period of flow of the inert gas between the period of exposure to the reducing gas and the period of exposure to the tungsten-containing precursor during each deposition cycle of the cyclical deposition process has the same duration.

31. The method of claim 21 wherein at least one period of flow of the inert gas between the period of exposure to the reducing gas and the period of exposure to the tungsten-containing precursor for one or more deposition cycle of the cyclical deposition process has a different duration.

32. The method of claim 21 wherein the tungsten-containing precursor is selected from the group consisting of tungsten hexafluoride (WF₆) and tungsten carbonyl (W(CO)₆).

33. The method of claims 21 wherein the reducing gas is selected from the group consisting of ammonia (NH₃), hydrazine (N₂H₄), monomethyl hydrazine (CH₃N₂H₃), dimethyl hydrazine (C₂H₆N₂H₂), t-butyl hydrazine (C₄H₉N₂H₃), phenyl hydrazine (C₆H₅N₂H₃), 2,2′

-azoisobutane ((CH₃)₆C₂N₂), ethylazide (C₂H₅N₃), silane (SiH₄), disilane (Si₂H₆), dichlorosilane (SiCl₂H₂), borane (BH₃), diborane (B₂H₆), triborane (B₃H₉), tetraborane (B₄H₁₂), pentaborane (B₅H₁₅), hexaborane (B₆H₁₈), heptaborane (B₇H₂₁), octaborane (B₈H₂₄), nanoborane (B₉H₂₇) and decaborane (B₁₀H₃₀), and combinations thereof.

34. The method of claim 21 wherein the tungsten-based layer comprises a material selected from the group consisting of tungsten (W), tungsten boride (W₂B) and tungsten nitride (WN).

35. A method of forming an electrode for a capacitor structure, comprising:

providing a substrate structure to a process chamber, wherein the substrate structure comprises an insulating material layer formed over a first electrode; and

depositing a tungsten-based layer on the substrate using a cyclical deposition process comprising a plurality of cycles, wherein each cycle comprises establishing a flow of an inert gas to the process chamber and modulating the flow of the inert gas with an alternating period of exposure to one of either a tungsten-containing precursor and a reducing gas, and wherein the tungsten-based layer comprises a second electrode.

36. The method of claim 35 wherein the period of exposure to the tungsten-containing precursor, the period of exposure to the reducing gas, a period of flow of the inert gas between the period of exposure to the tungsten-containing precursor and the period of exposure to the reducing gas, and a period of flow of the inert gas between the period of exposure to the reducing gas and the period of exposure to the tungsten-containing precursor each have the same duration.

37. The method of claim 35 wherein at least one of the period of exposure to the tungsten-containing precursor, the period of exposure to the reducing gas, a period of flow of the inert gas between the period of exposure to the tungsten-containing precursor and the period of exposure to the reducing gas, and a period of flow of the inert gas between the period of exposure to the reducing gas and the period of exposure to the tungsten-containing precursor has a different duration.

38. The method of claim 35 wherein the period of exposure to the tungsten-containing precursor during each deposition cycle of the cyclical deposition process has the same duration.

39. The method of claim 35 wherein at least one period of exposure to the tungsten-containing precursor for one or more deposition cycle of the cyclical deposition process has a different duration.

40. The method of claim 35 wherein the period of exposure to the reducing gas during each deposition cycle of the cyclical deposition process has the same duration.

41. The method of claim 35 wherein at least one period of exposure to the reducing gas for one or more deposition cycle of the cyclical deposition process has a different duration.

42. The method of claim 35 wherein a period of flow of the inert gas between the period of exposure to the tungsten-containing precursor and the period of exposure to the reducing gas during each deposition cycle of the cyclical deposition process has the same duration.

43. The method of claim 35 wherein at least one period of flow of the inert gas between the period of exposure to the tungsten-containing precursor and the period of exposure to the reducing gas for one or more deposition cycle of the cyclical deposition process has a different duration.

44. The method of claim 35 wherein a period of flow of the inert gas between the period of exposure to the reducing gas and the period of exposure to the tungsten-containing precursor during each deposition cycle of the cyclical deposition process has the same duration.

45. The method of claim 35 wherein at least one period of flow of the inert gas between the period of exposure to the reducing gas and the period of exposure to the tungsten-containing precursor for one or more deposition cycle of the cyclical deposition process has a different duration.

46. The method of claim 35 wherein the tungsten-containing precursor is selected from the group consisting of tungsten hexafluoride (WF₆) and tungsten carbonyl (W(CO)₆).

47. The method of claims 35 wherein the reducing gas is selected from the group consisting of ammonia (NH₃), hydrazine (N₂H₄), monomethyl hydrazine (CH₃N₂H₃), dimethyl hydrazine (C₂H₆N₂H₂), t-butyl hydrazine (C₄H₉N₂H₃), phenyl hydrazine (C₆H₅N₂H₃), 2,2′

-azoisobutane ((CH₃)₆C₂N₂), ethylazide (C₂H₅N₃), silane (SiH₄), disilane (Si₂H₆), dichlorosilane (SiCl₂H₂), borane (BH₃), diborane (B₂H₆), triborane (B₃H₉), tetraborane (B₄H₁₂), pentaborane (B₅H₁₅), hexaborane (B₆H₁₈), heptaborane (B₇H₂₁), octaborane (B₈H₂₄), nanoborane (B₉H₂₇) and decaborane (B₁₀H₃₀), and combinations thereof.

48. The method of claim 35 wherein the tungsten-based layer comprises a material selected from the group consisting of tungsten (W), tungsten boride (W₂B) and tungsten nitride (WN).

49. The method of claim 35 wherein the capacitor structure is a trench structure.

50. The method of claim 35 wherein the capacitor structure is a crown structure.

51. The method of claim 35 wherein the insulating material comprises a material selected from the group consisting of tantalum pentoxide (Ta₂O₅), silicon oxide/silicon nitride/oxynitride (ONO), aluminum oxide (Al₂O₃), barium strontium titanate (BST), barium titanate, lead zirconate titanate (PZT), lead lanthanium titanate, strontium titanate and strontium bismuth titanate.

52. The method of claim 35 wherein the first electrode comprises polysilicon.

53. The method of claim 35 wherein the first electrode comprises a tungsten-based layer formed using a cyclical deposition process.