Enhanced deposition of noble metals

• US 20070036892A1
• Filed: 03/14/2006
• Published: 02/15/2007
• Est. Priority Date: 03/15/2005
• Status: Active Grant

• Current Assignee: ASM International NV
• Original Assignee: ASM International NV
• Inventors: Tuominen, Marko, Haukka, Suvi, Rahtu, Antti
• Granted Patent: US 8,025,922 B2
• Time in Patent Office: Days
• US Class Current: 427/248.100
• CPC Class Codes: C23C 16/0218 in a reactive atmosphere C23C16/0227 takes precedence
• CPC Class Codes: C23C 16/08 from metal halides
• CPC Class Codes: C23C 16/18 from metallo-organic compounds
• CPC Class Codes: C23C 16/45525 Atomic layer deposition [ALD]
• CPC Class Codes: H01L 21/28562 Selective deposition

Abstract

The invention relates generally to processes for enhancing the deposition of noble metal thin films on a substrate by atomic layer deposition. Treatment with gaseous halides or metalorganic compounds reduces the incubation time for deposition of noble metals on particular surfaces. The methods may be utilized to facilitate selective deposition. For example, selective deposition of noble metals on high-k materials relative to insulators can be enhanced by pretreatment with halide reactants. In addition, halide treatment can be used to avoid deposition on the quartz walls of the reaction chamber.

Claims

1. A method for depositing a thin film comprising a noble metal on a substrate in a reaction chamber, the method comprising:

treating the substrate with a gaseous halide or metalorganic compound; and

depositing noble metal from a noble metal reactant that is different from the gaseous halide or metalorganic compound and an oxygen-containing reactant using a vapor phase deposition process.

2. The method of claim 1, wherein the vapor phase deposition process is a chemical vapor deposition process.

3. The method of claim 1, wherein the vapor phase deposition process is an atomic layer deposition process.

4. The method of claim 3, wherein the atomic layer deposition process comprises alternately and sequentially contacting the substrate with a noble metal precursor and a reactant gas comprising oxygen until a thin film of a desired thickness is obtained.

5. The method of claim 3, wherein the ALD process is carried out at a temperature below about 400°

C.

6. The method of claim 1, wherein treating comprises contacting the substrate with a gaseous halide.

7. The method of claim 1, wherein treating comprises contacting the substrate with a metalorganic compound.

8. The method of claim 1 wherein the halide is selected from the group consisting of hydrogen halides and metal halides.

9. The method of claim 1, wherein the halide is selected from the group consisting of HCl, AICl₃ and HfCl₄.

10. The method of claim 1, wherein treating is carried out a temperature between about 100°

C. and about 400°

C.

11. The method of claim 1, wherein the substrate comprises SiO₂.

12. The method of claim 10, wherein treating is carried out at a temperature greater than about 300°

C.

13. The method of claim 1, wherein the substrate comprises HfO₂.

14. The method of claim 1, wherein the noble metal reactant is a cyclopentadienyl or betadiketonate compound.

15. The method of claim 1, wherein the noble metal is ruthenium or iridium.

16. The method of claim 14, wherein the noble metal reactant is Ru(EtCp)₂.

17. The method of claim 1, additionally comprising a halide or organic ligand removal step between the treating and depositing steps.

18. The method of claim 17, wherein the substrate is contacted with a compound selected from the group consisting of water and ammonia.

22. The method of claim 1, wherein the first cycle additionally comprises a halide removal pulse.

23. The method of claim 22, wherein the halide removal pulse comprises providing water or ammonia to the reaction space.

19. An atomic layer deposition (ALD) process for depositing a thin film comprising a noble metal on a substrate in a reaction chamber, the method comprising a first and second cycle, wherein:

the first cycle comprises alternately and sequentially contacting the substrate with a vapor-phase halide and a noble metal precursor; and

the second cycle comprises alternately and sequentially contacting the substrate with the noble metal precursor and a reactant gas comprising oxygen.

21. The method of claim 19, wherein the second cycle is repeated until a thin film of the desired thickness is formed on the substrate.

24. The method of claim 19, wherein the noble metal precursor is a cyclopentadienyl compound.

25. The method of claim 19, wherein the first cycle and second cycle are conducted at different temperatures.

20. (canceled)

26. (canceled)

27. A method for selectively depositing a noble metal thin film on a first surface relative to a second surface, the method comprising:

a) contacting the first and second surfaces with a gaseous halide or organometallic compound at a temperature of less than about 300°

C.;

b) removing excess gaseous halide or organometallic compound;

c) contacting the substrate with a gaseous noble metal precursor to form no more than about a single molecular layer on the first surface;

d) removing excess noble metal precursor from the reaction chamber;

e) providing a second reactant gas pulse comprising oxygen to the reaction chamber;

f) removing excess second reactant gas and any reaction by-products from the reaction chamber; and

repeating steps c) through f) until a thin film is obtained on the first surface relative to the second surface,

wherein the first surface is a high k material and the second surface comprises SiO₂.

28. The process of claim 27, wherein the noble metal thin film is not formed on the second surface.

29. The process of claim 27, wherein the noble metal thin film that is obtained is thicker on the first surface than on the second surface.

30. The process of claim 27, wherein the second surface is SiO₂.

32. The process of claim 27, wherein the noble metal is ruthenium.

34. The process of claim 27, wherein the first surface comprises a high-k material.

35. The process of claim 27 wherein the high-k material is selected from the group consisting of HfO₂, ZrO₂, Al₂O₃, TiO₂, Ta₂O₅, lanthanide oxides and mixtures thereof, silicates, yttria-stabilized zirconia (YSZ), barium strontium titanate (BST), strontium titanate (ST), strontium bismuth tantalate (SBT) and bismuth tantalate (BT).

39. The method of claim 29, wherein the substrate comprises one or more of HfO₂, Al₂O₃ and silicon.

40. The method of claim 29, wherein the noble metal reactant is a cyclopentadienyl reactant.

41. The method of claim 29, wherein the noble metal is ruthenium.

31. (canceled)

33. (canceled)

36. (canceled)

37. (canceled)

38. A method for depositing a noble metal on a substrate in a reaction chamber comprising quartz walls while avoiding deposition on the reaction chamber walls, the method comprising:

providing a gaseous halide or metalorganic compound to the reaction chamber at a temperature of less than about 300°

C.;

removing excess halide; and

depositing noble metal on the substrate by an atomic layer deposition process (ALD) from a noble metal reactant and an oxygen reactant at a temperature less than or equal to 300°

C.

42. (canceled)

43. A method of forming a thin film comprising a noble metal on a substrate in a reaction chamber, the method comprising:

a) depositing a first film on the substrate by an atomic layer deposition (ALD) process comprising alternate and sequential pulses of a metal reactant and a second reactant, wherein the metal reactant is a halide or metalorganic compound;

b) treating the deposited first film with the metal reactant; and

c) depositing the thin film comprising a noble metal by ALD.

44. The method of claim 43, wherein the first film is a metal oxide.

45. The method of claim 44, wherein the first film is a hafnium oxide film.

46. The method of claim 43, wherein the metal reactant is HfCl₄ or TEMAH.

47. The method of claim 43, wherein the noble metal is ruthenium.

48-52. -52. (canceled)