PLASMA-ENHANCED DEPOSITION OF METAL CARBIDE FILMS

• US 20080113110A1
• Filed: 10/16/2007
• Published: 05/15/2008
• Est. Priority Date: 10/25/2006
• Status: Active Grant

• Current Assignee: ASM IP Holding B.V. (ASM International NV)
• Original Assignee: ASM America Incorporated (ASM International NV)
• Inventors: Elers, Kai-Erik, Marcus, Steven, Wilk, Glen
• Granted Patent: US 8,268,409 B2
• Time in Patent Office: Days
• US Class Current: 427/577
• CPC Class Codes: C23C 16/32 Carbides
• CPC Class Codes: C23C 16/45527 characterized by the ALD cycle, e.g. different flows or temperatures during half-reactions, unusual pulsing sequence, use of precursor mixtures or auxiliary reactants or activations
• CPC Class Codes: C23C 16/45542 Plasma being used non-continuously during the ALD reactions
• CPC Class Codes: C23C 16/515 using pulsed discharges

Abstract

Methods of forming a metal carbide film are provided. In some embodiments, methods for forming a metal carbide film in an atomic layer deposition (ALD) type process comprise alternately and sequentially contacting a substrate in a reaction space with vapor phase pulses of a metal compound and one or more plasma-excited species of a carbon-containing compound. In other embodiments, methods of forming a metal carbide film in a chemical vapor deposition (CVD) type process comprise simultaneously contacting a substrate in a reaction space with a metal compound and one or more plasma-excited species of a carbon-containing compound. The substrate is further exposed to a reducing agent. The reducing agent removes impurities, including halogen atoms and/or oxygen atoms

Claims

1. A method for growing a metal carbide film over a substrate in a reaction space, comprising:

contacting the substrate with a first reactant that includes a metal source chemical;

contacting the substrate with a second reactant that includes one or more plasma-excited species of a carbon-containing compound, thereby forming the metal carbide film over the substrate; and

contacting the substrate with a third reactant, wherein the third reactant is a reducing agent.

2. The method of claim 1, wherein contacting the substrate with the reducing agent is performed between contacting the substrate with the first reactant and contacting the substrate with the second reactant.

3. The method of claim 1, wherein contacting the substrate with the reducing agent is performed after contacting the substrate with the first reactant and before again contacting the substrate with the second reactant.

4. The method of claim 3, wherein contacting the substrate with the reducing agent is further performed between contacting the substrate with the first reactant and contacting the substrate with the second reactant

5. The method of claim 1, wherein contacting the substrate with the reducing agent comprises contacting the substrate with a plasma-excited species.

6. The method of claim 5, wherein contacting the plasma-excited species includes one or more plasma-excited species of hydrogen (H₂).

7. The method of claim 1, further comprising removing any excess first and second reactants and reaction byproducts from the reaction space.

8. The method of claim 1, wherein the metal carbide film is substantially uniform.

9. The method of claim 1, wherein contacting comprises performing an atomic layer deposition (ALD) process comprising alternately and sequentially contacting the substrate with the first and second reactants.

10. The method of claim 1, wherein contacting comprises performing a chemical vapor deposition (CVD) process comprising simultaneously contacting the substrate with the first and second reactants.

11. The method of claim 1, wherein the carbon-containing compound does not contain boron.

12. The method of claim 1, wherein the metal carbide film forms part of a conductive diffusion barrier in an integrated circuit (IC).

13. The method of claim 12, wherein the conductive diffusion barrier forms part of a line in a dual damascene structure.

14. The method of claim 12, wherein the metal carbide film forms part of a metal gate in an integrated circuit (IC).

15. The method of claim 1, wherein the metal carbide film forms an etch stop barrier.

16. The method of claim 1, wherein the metal source chemical includes TaF₅.

17. The method of claim 1, wherein the carbon-containing compound includes CH₄.

18. The method of claim 1, wherein the one or more plasma-excited species of the carbon-containing compound are formed in the reaction space.

19. The method of claim 1, wherein the one or more plasma-excited species of the carbon-containing compound are formed in a remote plasma generator.

20. An atomic layer deposition (ALD) process for growing a metal carbide film over a substrate, comprising:

alternately and sequentially contacting a substrate in a reaction space with vapor phase pulses of;

a metal compound that forms no more than about one monolayer of a metal-containing film on an exposed surface of the substrate; and

one or more plasma-excited species of a carbon-containing compound; and

exposing the substrate to one or more vapor phase pulses of a reducing agent between pulses of the metal compound and the carbon-containing compound.

21. The process of claim 20, wherein the reducing agent includes one or more plasma-excited species of hydrogen.

22. The process of claim 20, wherein a pulse of the metal compound and an immediately following pulse of the carbon-containing compound constitute one cycle, wherein exposing the substrate to one or more vapor phase pulses of the reducing agent is performed once per plurality of cycles.

23. The process of claim 20, wherein the one or more plasma-excited species react with the metal-containing film to form no more than about one monolayer of a metal carbide film over the substrate.

24. The process of claim 20, further comprising removing any excess metal compound after the vapor phase pulse of the metal compound.

25. The process of claim 24, wherein removing comprises purging the reaction space with a gas selected from the group consisting of argon (Ar), helium (He) and hydrogen (H₂).

26. The process of claim 24, wherein removing comprises pumping the reaction space.

27. The process of claim 20, further comprising removing any reaction byproducts after each of said pulses

28. The process of claim 20, further comprising removing any excess one or more plasma-excited species of the carbon-containing compound after the vapor phase pulse of the one or more plasma-excited species of the carbon-containing compound.

29. The process of claim 20, wherein the metal compound comprises at least one metal selected from the group consisting of titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), manganese (Mn), rhenium (Re), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), silver (Ag), gold (Au), palladium (Pd), platinum (Pt), rhodium (Rh), iridium (Ir), rutenium (Ru), and osmium (Os).

30. The process of claim 20, wherein the metal compound is selected from the group consisting of metal halides and metal organic compounds.

31. The process of claim 30, wherein the metal compound is selected from the group consisting of metal bromides, metal chlorides, metal fluorides and metal iodides.

32. The method of claim 31, wherein the metal source chemical is TaF₅.

33. The process of claim 30, wherein the metal compound is selected from the group consisting of metal dialkylamido and metal cyclopentadienyl compounds.

34. The process of claim 20, wherein the carbon-containing compound is a hydrocarbon.

35. The process of claim 34 wherein the hydrocarbon is selected from the group consisting of alkanes, alkenes and alkynes.

36. The process of claim 34, wherein the hydrocarbon is methane (CH₄).

37. The process of claim 20, wherein the metal compound is introduced into the reaction space with the aid of a carrier gas.

38. The process of claim 20, wherein the one or more plasma-excited species include carbon-containing radicals formed from the carbon-containing compound.

39. A method for growing a metal carbide film over a substrate in a reaction space by a chemical vapor deposition (CVD) process, comprising simultaneously contacting the substrate with a metal compound and one or more plasma-excited species of a carbon-containing compound to form the metal carbide film, further comprising contacting the substrate with a reducing agent.

40. The method of claim 39, further comprising removing any excess metal compound, one or more plasma-excited species of the carbon-containing compound and reaction byproducts from the reaction space

41. The method of claim 39, wherein the metal carbide film comprises one or more metals selected from the group consisting of titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo), tungsten (W), manganese (Mn), rhenium (Re), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), silver (Ag), gold (Au), palladium (Pd), platinum (Pt), rhodium (Rh), iridium (Ir), rutenium (Ru) and osmium (Os).

42. The method of claim 39, wherein the metal compound is selected from the group consisting of metal halides and metal organic compounds.

43. The method of claim 42, wherein the metal compound is selected from the group consisting of metal bromides, metal chlorides, metal fluorides and metal iodides.

44. The method of claim 43, wherein the metal compound is TaF₅.

45. The method of claim 42, wherein the metal compound is selected from the group consisting of metal dialkylamido and metal cyclopentadienyl compounds.

46. The method of claim 39, wherein the carbon-containing compound is a hydrocarbon.

47. The method of claim 46, wherein the hydrocarbon is selected from the group consisting of alkanes, alkenes and alkynes.

48. The method of claim 46, wherein the hydrocarbon is methane (CH₄).

49. The method of claim 48, wherein the reducing agent includes one or more plasma-excited species of hydrogen (H₂).

50. The method of claim 39, wherein the metal compound is introduced into the reaction space with the aid of a carrier gas.

51. The method of claim 39, wherein the one or more plasma-excited species of the carbon-containing compound include carbon-containing radicals formed from the carbon-containing compound.