Ruthenium layer formation for copper film deposition

• US 20040241321A1
• Filed: 03/26/2004
• Published: 12/02/2004
• Est. Priority Date: 06/04/2002
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Chang, Mei, Shah, Kavita, Maity, Nirmaya, Ganguli, Seshadri
• Granted Patent: US 7,910,165 B2
• Time in Patent Office: Days
• US Class Current: 427/255.28
• CPC Class Codes: C23C 16/18 from metallo-organic compounds
• CPC Class Codes: C23C 16/45553 characterized by the use of precursors specially adapted for ALD
• CPC Class Codes: H01L 21/28562 Selective deposition
• CPC Class Codes: H01L 21/76843 formed in openings in a dielectric
• CPC Class Codes: H01L 21/76871 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

Abstract

A method of ruthenium layer formation for high aspect ratios, interconnect features is described. The ruthenium layer is formed using a cyclical deposition process. The invention generally provides a method of forming a film on a substrate surface including positioning a substrate within a process chamber, exposing a ruthenium-containing compound to the substrate surface, purging the process chamber with a purge gas, reducing the ruthenium-containing compound with a reductant to form a ruthenium layer on the substrate surface and purging the process chamber with the purge gas. The ruthenium-containing compound is selected from the group consisting of bis(dialkylpentadienyl)ruthenium compounds, bis(alkylpentadienyl) ruthenium compounds, bis(pentadienyl)ruthenium compounds, and combinations thereof.

Claims

1. A method of forming a film on a substrate surface, comprising:

positioning a substrate within a process chamber;

exposing a ruthenium-containing compound to the substrate surface, wherein the ruthenium-containing compound is selected from the group consisting of bis(dialkylpentadienyl)ruthenium compounds, bis(alkylpentadienyl)ruthenium compounds, bis(pentadienyl)ruthenium compounds, and combinations thereof;

purging the process chamber with a purge gas;

reducing the ruthenium-containing compound with a reductant to form a ruthenium layer on the substrate surface; and

purging the process chamber with the purge gas.

2. The method of claim 1, wherein the ruthenium-containing compound comprises at least one alkyl group selected from the group consisting of methyl, ethyl, propyl, butyl and combinations thereof.

3. The method of claim 2, wherein the at least one alkyl group is methyl.

4. The method of claim 2, wherein the ruthenium-containing compound is selected from the group consisting of bis(2,4-dimethylpentadienyl)ruthenium, bis(2,4-diethylpentadienyl)ruthenium, bis(2,4-diisopropylpentadienyl)ruthenium, bis(2,4-ditertbutylpentadienyl)ruthenium, bis(methylpentadienyl)ruthenium, bis(ethylpentadienyl)ruthenium, bis(isopropylpentadienyl)ruthenium, bis(tertbutylpentadienyl)ruthenium, and combinations thereof.

5. The method of claim 4, wherein the reductant comprises one or more reagents selected from the group consisting of oxygen, nitrous oxide, nitric oxide, nitrogen dioxide, and combinations thereof.

6. The method of claim 5, wherein the ruthenium layer is formed at a temperature in a range from about 200°

C. to about 400°

C.

7. The method of claim 6, wherein a thickness of the ruthenium layer is about 100 Å

and the ruthenium layer has a resistivity less than 15 μ

Ω

-cm.

8. The method of claim 6, wherein the ruthenium layer has a sheet resistance less than 2,000 Ω

/sq.

9. The method of claim 4, wherein the substrate surface further comprises a barrier layer selected from the group consisting of tantalum, tantalum nitride, tantalum silicon nitride, titanium, titanium nitride, titanium silicon nitride, tungsten, tungsten nitride, and combinations there.

10. The method of claim 4, wherein the substrate surface further comprises at least one low-k material selected from the group consisting of silicon dioxide, silicon nitride, silicon oxynitride, carbon-doped silicon oxides, SiO_xC_y, and combinations there.

11. A method for forming a layer comprising ruthenium on a substrate surface within a process chamber, sequentially comprising:

a) exposing the substrate surface to bis(2,4-dimethylpentadienyl)ruthenium to form a ruthenium-containing layer on the substrate surface;

b) purging the process chamber with a purge gas;

c) reacting a reducing gas with the ruthenium-containing layer; and

d) purging the process chamber with the purge gas.

12. The method of claim 11, wherein the reducing gas comprises one or more reagents selected from the group consisting of oxygen, nitrous oxide, nitric oxide, nitrogen dioxide, and combinations thereof.

13. The method of claim 12, wherein the layer is formed at a temperature in a range from about 200°

C. to about 400°

C.

14. The method of claim 13, wherein a thickness of the ruthenium layer is about 100 Å

and the ruthenium layer has a resistivity less than 15 μ

Ω

-cm.

15. The method of claim 13, wherein the ruthenium layer has a sheet resistance less than 2,000 Ω

/sq.

16. The method of claim 12, wherein the ruthenium layer on the substrate surface further comprises a barrier layer selected from the group consisting of tantalum, tantalum nitride, tantalum silicon nitride, titanium, titanium nitride, titanium silicon nitride, tungsten, tungsten nitride, and combinations there.

17. The method of claim 12, wherein the substrate surface further comprises at least one low-k material selected from the group consisting of silicon dioxide, silicon nitride, silicon oxynitride, carbon-doped silicon oxides, SiO_xC_y, and combinations there.

18. A method of forming a ruthenium layer on a substrate for use in integrated circuit fabrication, comprising:

depositing a barrier layer to a substrate surface by a first ALD process, wherein the barrier layer is selected from the group consisting of tantalum, tantalum nitride, tantalum silicon nitride, titanium, titanium nitride, titanium silicon nitride, tungsten, tungsten nitride and combinations thereof; and

depositing the ruthenium layer to the barrier layer by a second ALD process, comprising;

exposing the barrier layer to a ruthenium-containing compound within a process chamber;

chemisorbing a ruthenium-containing layer to the barrier layer;

exposing the ruthenium-containing layer to a reducing gas; and

reacting the reducing gas with the ruthenium-containing layer to form the ruthenium layer on the barrier layer.

19. The method of claim 18, wherein the ruthenium-containing compound is selected from the group consisting of bis(dialkylpentadienyl)ruthenium compounds, bis(alkylpentadienyl)ruthenium compounds, bis(pentadienyl)ruthenium compounds, and combinations thereof.

20. The method of claim 19, wherein the ruthenium-containing compound comprises at least one alkyl group selected from the group consisting of methyl, ethyl, propyl, butyl and combinations thereof.

21. The method of claim 20, wherein the at least one alkyl group is methyl.

22. The method of claim 19, wherein the ruthenium-containing compound is selected from the group consisting of bis(2,4-dimethylpentadienyl)ruthenium, bis(2,4-diethylpentadienyl)ruthenium, bis(2,4-diisopropylpentadienyl)ruthenium, bis(2,4-ditertbutylpentadienyl)ruthenium, bis(methylpentadienyl)ruthenium, bis(ethylpentadienyl) ruthenium, bis(isopropylpentadienyl) ruthenium, bis(tertbutylpentadienyl)ruthenium, and combinations thereof.

23. The method of claim 18, wherein the reducing gas comprises one or more reagents selected from the group consisting of oxygen, nitrous oxide, nitric oxide, nitrogen dioxide, and combinations thereof.

24. The method of claim 23, wherein the ruthenium layer is formed at a temperature in a range from about 200°

C. to about 400°

C.

25. The method of claim 24, wherein a thickness of the ruthenium layer is about 100 Å

and the ruthenium layer has a resistivity less than 15 μ

Ω

-cm.

26. The method of claim 24, wherein the ruthenium layer has a sheet resistance less than 2,000 Ω

/sq.

27. A method of forming a ruthenium film on a dielectric material on a substrate, comprising:

positioning the substrate within a process chamber;

exposing a ruthenium-containing compound to the dielectric material, wherein the ruthenium-containing compound is selected from the group consisting of bis(dialkylpentadienyl)ruthenium compounds, bis(alkylpentadienyl)ruthenium compounds, bis(pentadienyl)ruthenium compounds, and combinations thereof;

purging the process chamber with a purge gas;

reducing the ruthenium-containing compound with a reductant to form the ruthenium layer on the dielectric material; and

purging the process chamber with the purge gas.

28. The method of claim 27, wherein the ruthenium-containing compound comprises at least one alkyl group selected from the group consisting of methyl, ethyl, propyl, butyl and combinations thereof.

29. The method of claim 28, wherein the at least one alkyl group is methyl.

30. The method of claim 28, wherein the ruthenium-containing compound is selected from the group consisting of bis(2,4-dimethylpentadienyl)ruthenium, bis(2,4-diethylpentadienyl)ruthenium, bis(2,4-diisopropylpentadienyl)ruthenium, bis(2,4-ditertbutylpentadienyl)ruthenium, bis(methylpentadienyl)ruthenium, bis(ethylpentadienyl)ruthenium, bis(isopropylpentadienyl)ruthenium, bis(tertbutylpentadienyl)ruthenium, and combinations thereof.

31. The method of claim 27, wherein the reductant comprises one or more reagents selected from the group consisting of oxygen, nitrous oxide, nitric oxide, nitrogen dioxide, and combinations thereof.

32. The method of claim 31, wherein the ruthenium layer is formed at a temperature in a range from about 200°

C. to about 400°

C.

33. The method of claim 32, wherein a thickness of the ruthenium layer is about 100 Å

and the ruthenium layer has a resistivity less than 15 μ

Ω

-cm.

34. The method of claim 32, wherein the ruthenium layer has a sheet resistance less than 2,000 Ω

/sq.

35. The method of claim 30, wherein the dielectric material comprises at least one low-k material selected from the group consisting of silicon dioxide, silicon nitride, silicon oxynitride, carbon-doped silicon oxides, SiO_xC_y, and combinations there.

36. A method of forming a ruthenium layer on a substrate surface, comprising:

positioning a substrate within a process chamber;

exposing the substrate surface to a ruthenium-containing compound comprising ruthenium and at least one open chain dienyl ligand;

forming a ruthenium-containing compound film on the substrate surface;

purging the process chamber with a purge gas;

reducing the ruthenium-containing compound film with a reductant comprising at least one reagent selected from the group consisting of oxygen, nitrous oxide, nitric oxide, nitrogen dioxide, and combinations; and

purging the process chamber with the purge gas.

37. The method of claim 36, wherein the ruthenium-containing compound is selected from the group consisting of bis(dialkylpentadienyl)ruthenium compounds, bis(alkylpentadienyl)ruthenium compounds, bis(pentadienyl)ruthenium compounds, and combinations thereof.

38. The method of claim 37, wherein the ruthenium-containing compound comprises at least one alkyl group selected from the group consisting of methyl, ethyl, propyl, butyl and combinations thereof.

39. The method of claim 38, wherein the at least one alkyl group is methyl.

40. The method of claim 36, wherein the ruthenium-containing compound is selected from the group consisting of bis(2,4-dimethylpentadienyl)ruthenium, bis(2,4-diethylpentadienyl)ruthenium, bis(2,4-diisopropylpentadienyl)ruthenium, bis(2,4-ditertbutylpentadienyl)ruthenium, bis(methylpentadienyl)ruthenium, bis(ethylpentadienyl)ruthenium, bis(isopropylpentadienyl)ruthenium, bis(tertbutylpentadienyl)ruthenium, and combinations thereof.

41. The method of claim 40, wherein the ruthenium layer is formed at a temperature in a range from about 200°

C. to about 400°

C.

42. The method of claim 41, wherein a thickness of the ruthenium layer is about 100 Å

and the ruthenium layer has a resistivity less than 15 μ

Ω

-cm.

43. The method of claim 41, wherein the ruthenium layer has a sheet resistance less than 2,000 Ω

/sq.

44. A method of forming a ruthenium layer on a low-k material, comprising:

positioning a substrate containing the low-k material within a process chamber;

maintaining the substrate at a temperature in a range from about 200°

C. to about 400°

C.;

exposing the low-k material with a ruthenium-containing compound comprising ruthenium and at least one open chain dienyl ligand;

forming a ruthenium-containing compound film on the low-k material;

purging the process chamber with a purge gas;

reducing the ruthenium-containing compound film with a reductant comprising an oxygen-containing gas; and

purging the process chamber with the purge gas.

45. The method of claim 44, wherein the temperature is in a range from about 300°

C. to about 350°

C.

46. The method of claim 45, wherein a thickness of the ruthenium layer is about 100 Å

and the ruthenium layer has a resistivity less than 15 μ

Ω

-cm.

47. The method of claim 45, wherein the ruthenium layer has a sheet resistance less than 2,000 Ω

/sq.

48. The method of claim 44, wherein the low-k material comprises at least one material selected from the group consisting of silicon dioxide, silicon nitride, silicon oxynitride, carbon-doped silicon oxides, SiO_xC_y, and combinations there.

49. The method of claim 48, wherein the oxygen-containing gas comprises at least one reagent selected from the group consisting of oxygen, nitrous oxide, nitric oxide, nitrogen dioxide, and combinations.

50. The method of claim 49, wherein the ruthenium-containing compound is selected from the group consisting of bis(dialkylpentadienyl)ruthenium compounds, bis(alkylpentadienyl)ruthenium compounds, bis(pentadienyl)ruthenium compounds, and combinations thereof.

51. The method of claim 50, wherein the ruthenium-containing compound comprises at least one alkyl group selected from the group consisting of methyl, ethyl, propyl, butyl and combinations thereof.

52. The method of claim 51, wherein the at least one alkyl group is methyl.

53. The method of claim 48, wherein the ruthenium-containing compound is selected from the group consisting of bis(2,4-dimethylpentadienyl)ruthenium, bis(2,4-diethylpentadienyl)ruthenium, bis(2,4-diisopropylpentadienyl)ruthenium, bis(2,4-ditertbutylpentadienyl)ruthenium, bis(methylpentadienyl)ruthenium, bis(ethylpentadienyl)ruthenium, bis(isopropylpentadienyl)ruthenium, bis(tertbutylpentadienyl)ruthenium, and combinations thereof.

54. A method of forming a ruthenium-containing layer on a low-k material, comprising:

positioning a substrate containing the low-k material within a process chamber;

maintaining the substrate at a temperature in a range from about 200°

C. to about 400°

C.;

exposing the low-k material to bis(2,4-dimethylpentadienyl)ruthenium to form a ruthenium-containing compound film;

purging the process chamber with a purge gas;

reducing the ruthenium-containing compound film with a gas comprising oxygen; and

purging the process chamber with the purge gas.

55. A method of forming a ruthenium-containing layer on a copper-barrier material, comprising:

positioning a substrate containing a tantalum-containing material within a process chamber;

maintaining the substrate at a temperature in a range from about 200°

C. to about 400°

C.;

exposing the tantalum-containing material to bis(2,4-dimethylpentadienyl)ruthenium to form a ruthenium-containing compound film;

purging the process chamber with a purge gas;

reducing the ruthenium-containing compound film with a gas comprising oxygen; and

purging the process chamber with the purge gas.