Enhanced thin film deposition

• US 20070148350A1
• Filed: 10/27/2006
• Published: 06/28/2007
• Est. Priority Date: 10/27/2005
• Status: Active Grant

• Current Assignee: ASM International NV
• Original Assignee: ASM International NV
• Inventors: Elers, Kai-Erik, Tois, Eva, Li, Wei-Min, Rahtu, Antti
• Granted Patent: US 8,993,055 B2
• Time in Patent Office: Days
• US Class Current: 427/249.170
• CPC Class Codes: C23C 16/32 Carbides
• CPC Class Codes: C23C 16/45525 Atomic layer deposition [ALD]
• CPC Class Codes: C23C 16/45531 specially adapted for making ternary or higher compositions
• CPC Class Codes: C23C 16/45534 Use of auxiliary reactants other than used for contributing to the composition of the main film, e.g. catalysts, activators or scavengers
• CPC Class Codes: C23C 16/45553 characterized by the use of precursors specially adapted for ALD
• CPC Class Codes: H01L 21/02107 Forming insulating materials on a substrate
• CPC Class Codes: H01L 21/02205 the layer being characterised by the precursor material for deposition
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• CPC Class Codes: H01L 21/28088 the final conductor layer next to the insulator being a composite, e.g. TiN
• CPC Class Codes: H01L 21/285 from a gas or vapour, e.g. condensation
• CPC Class Codes: H01L 21/28562 Selective deposition
• CPC Class Codes: H01L 21/312 Organic layers, e.g. photoresist H01L21/3105, H01L21/32 take precedence; photoresists per se G03C
• CPC Class Codes: H01L 21/3141 Deposition using atomic layer deposition techniques [ALD]
• CPC Class Codes: H01L 21/31604 Deposition from a gas or vapour H01L21/31691, H01L21/31695 take precedence
• CPC Class Codes: H01L 21/31637 Deposition of Tantalum oxides, e.g. Ta2O5
• CPC Class Codes: H01L 21/31641 Deposition of Zirconium oxides, e.g. ZrO2
• CPC Class Codes: H01L 21/31645 Deposition of Hafnium oxides, e.g. HfO2
• CPC Class Codes: H01L 21/3205 Deposition of non-insulating-, e.g. conductive- or resistive-, layers on insulating layers; After-treatment of these layers manufacture of electrodes H01L21/28
• CPC Class Codes: H01L 21/32055 Deposition of semiconductive layers, e.g. poly - or amorphous silicon layers
• CPC Class Codes: H01L 21/32056 Deposition of conductive or semi-conductive organic layers H01L21/32058 takes precedence
• CPC Class Codes: H01L 21/76843 : formed in openings in a dielectric

Abstract

Methods of producing metal-containing thin films with low impurity contents on a substrate by atomic layer deposition (ALD) are provided. The methods preferably comprise contacting a substrate with alternating and sequential pulses of a metal source chemical, a second source chemical and a deposition enhancing agent. The deposition enhancing agent is preferably selected from the group consisting of hydrocarbons, hydrogen, hydrogen plasma, hydrogen radicals, silanes, germanium compounds, nitrogen compounds, and boron compounds. In some embodiments, the deposition-enhancing agent reacts with halide contaminants in the growing thin film, improving film properties.

Claims

1. An atomic layer deposition (ALD) process for forming a metal carbide thin film comprising a plurality of deposition cycles, at least one cycle comprising contacting a substrate in a reaction space with alternating and sequential pulses of a first source chemical that comprises at least one halide ligand and a metal that is to be included in the thin film, a second source chemical comprising metal and carbon, wherein carbon from the second source chemical is incorporated into the thin film, and a third source chemical, wherein the third source chemical is a deposition-enhancing agent.

2. The process of claim 1, wherein in at least one cycle the substrate is contacted with the second source chemical before being contacted with the third source chemical.

3. The process of claim 1, wherein the deposition-enhancing agent is selected from the group consisting of hydrocarbons, hydrogen, hydrogen plasma, hydrogen radicals, silanes, germanium compounds, nitrogen compounds, boron compounds and boranes.

4. The process of claim 3, wherein the deposition enhancing agent is a hydrocarbon.

5. The method of claim 4, wherein the hydrocarbon is selected from the group consisting of alkanes, alkenes and alkynes.

6. The process of claim 5, wherein the deposition-enhancing agent is acetylene (C₂H₂).

7. The process of claim 1, wherein the deposition enhancing-agent comprises hydrogen radicals.

8. The process of claim 1, wherein the deposition-enhancing agent is provided in each of the plurality of deposition cycles.

9. The process of claim 1, wherein the second source chemical comprises at least one organic ligand.

10. The process of claim 9, wherein the organic ligand is selected from the group consisting of cyclopentadienyl, alkoxide, alkyl, carbonyl, cyclo-octadiene, and benzene ligands.

11. The process of claim 10, wherein the alkyl ligand is selected from the group consisting of methyl and ethyl groups.

12. The process of claim 1, wherein the second source chemical comprises a metal selected from the group consisting of B, Al, In, Sn, Bi, Sn, Zn, Pb, Sb and Ga.

13. The process of claim 1, wherein the second source chemical is trimethylaluminum (TMA) or triethylaluminum (TEA).

14. The process of claim 1, wherein the first metal source chemical comprises a metal selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, and Al.

15. The process of claim 17, wherein the first metal source chemical is selected from the group consisting of SiCl₄, TiCl₄, ZrC₄, HfCl₄, VCl₅, NbCl₅, NbF₅, TaCl₅, TaF₅, CrCl₄, MoCl₅, MoF₅, MoF₆, WCl₅, WCl₆, WF₆ and AlCl_3.

16. The process of claim 1, wherein the first reactant is TaCl₅, the second reactant is TMA and the third reactant is C₂H₂.

17. The process of claim 1, wherein the pulses are separated from each other by time and the reaction chamber is purged with an inactive gas or evacuated between the pulses to remove surplus source chemicals and reaction by-products from the chamber.

18. The process of claim 1, wherein the deposition-enhancing agent reacts with halide contaminants in the growing thin film.

19. The process of claim 1, wherein the at least one deposition cycle comprises:

contacting the substrate with a transition metal halide;

removing excess transition metal halide from the reaction space;

contacting the substrate with an organometallic or metalorganic compound;

removing excess organometallic or metalorganic compound from the reaction space; and

contacting the substrate with hydrogen radicals.

20. A method for depositing a metal carbide thin film on a substrate in a reaction chamber, the method comprising providing alternating, self-saturating pulses of reactants in a plurality of deposition cycles, each cycle comprising contacting a substrate in a reaction space with separate pulses of a first metal source chemical, a second source chemical comprising carbon and a third source chemical, wherein the third source chemical is a hydrocarbon.

24. The method of claim 24, wherein the third source chemical is selected from the group consisting of alkanes, alkenes, and alkynes.

21. The method of claim 24, wherein the metal source chemical is a halide compound.

22. The method of claim 24, wherein the second source chemical is a metalorganic compound.

23. The method of claim 24, wherein the second source chemical is TMA or TEA.

25. The method of claim 28, wherein the third source chemical is acetylene.

26. The method of claim 24, wherein the second source chemical is the next source chemical provided after the first metal source chemical.

27. The method of claim 24, wherein the second source chemical is the next source chemical provided after the third source chemical.

28. The method of claim 24, wherein the third source chemical removes some halides from the growing thin film.

29. A method of depositing a metal oxide thin film on a substrate in a reaction space by an atomic layer deposition process, the atomic layer deposition process comprising a plurality of deposition cycles, each cycle comprising supplying separate pulses of:

a metal reactant;

a second reactant comprising an oxygen source; and

a third reactant that is a hydrocarbon.

33. An atomic layer deposition (ALD) process for forming an elemental metal thin film on a substrate, the process comprising contacting the substrate with alternating and sequential pulses of a deposition-enhancing agent, a metal source chemical, and a reducing agent selected from the group consisting of boranes and silanes.

30. The method of claim 33, wherein the third reactant removes halides from the growing thin film.

31. The method of claim 33, wherein the metal reactant comprises a metal selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W and Al.

32. The method of claim 33, wherein the oxygen source is selected from the group consisting of H₂O, O₂, ozone, oxygen radicals and oxygen plasma.

34. The process of claim 44, wherein the metal source chemical is a halide.

35. The process of claim 44, wherein the deposition-enhancing agent reacts with halide contaminants in the growing thin film.

36. An atomic layer deposition (ALD) process for forming a silicon-containing thin film on a substrate, the process comprising contacting the substrate with alternating and sequential pulses of a metal source chemical, a silicon source chemical and a deposition-enhancing agent.

37. The process of claim 55, wherein the silicon-containing thin film comprises a metal silicide.

38. The process of claim 55, wherein the silicon source chemical is a silane (Si_xH_y).

39. The process of claim 55, wherein the deposition-enhancing agent is selected from the group consisting of hydrocarbons, hydrogen, hydrogen plasma, hydrogen radicals, silanes germanium compounds, boron compounds and boranes.

40. An atomic layer deposition process for depositing a metal or silicon-containing thin film on a substrate using at least three source chemicals, wherein at least one of the source chemicals is a hydrocarbon.

41. The process of claim 67, wherein the hydrocarbon is selected from the group consisting of alkanes, alkenes and alkynes.

42. The process of claim 68, wherein the hydrocarbon is acetylene.

43. The process of claim 68, wherein the hydrocarbon removes contaminants from thin film.