Enhanced thin film deposition

• US 8,993,055 B2
• Filed: 10/27/2006
• Issued: 03/31/2015
• Est. Priority Date: 10/27/2005
• Status: Active Grant

• Current Assignee: ASM International NV
• Original Assignee: ASM International NV
• Inventors: Rahtu, Antti, Tois, Eva, Elers, Kai-Erik, Li, Wei-Min
• Primary Examiner(s): CHEN, BRET P
• Application Number:
  US11/588,837
• Publication Number:
  US 20070148350A1
• Time in Patent Office: 3,077 Days
• Field of Search: 427/248.17, 427/250, 427/249.17, 427/255.31, 427/255.39
• US Class Current: 427/249.17
• 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 tantalum carbide thin film comprising a plurality of first 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 a tantalum halide compound, a second source chemical comprising metal and carbon, wherein carbon from the second source chemical is incorporated into the thin film, and a third reactant wherein the third reactant is a deposition-enhancing agent that is acetylene (C₂H₂).

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 reactant.

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

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

5. The process of claim 4, wherein the organic ligand is selected from the group consisting of cyclopentadienyl, alkoxide, alkyl, carbonyl, cyclo-octadiene, and benzene ligands.

6. The process of claim 5, wherein the alkyl ligand is selected from the group consisting of methyl and ethyl groups.

7. 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.

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

9. The process of claim 1, wherein the first metal source chemical is TaCl₅ or TaF₅.

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

11. 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.

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

13. The process of claim 1, further comprising a second deposition cycle comprising contacting the substrate 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, and a second source chemical comprising metal and carbon, wherein carbon from the second source chemical is incorporated into the thin film, wherein no deposition-enhancing agent is used in the second deposition cycle.

14. The process of claim 13, wherein the second deposition cycle is repeated up to 10 times before performing the first deposition cycle.

15. A method for depositing a tantalum carbide thin film on a substrate in a reaction chamber, the method comprising providing alternating, self-saturating pulses of reactants in a plurality of first deposition cycles, each cycle comprising contacting a substrate in a reaction space with separate pulses of a first metal source chemical comprising a tantalum halide, a second source chemical comprising carbon and a third source chemical, wherein the third source chemical is acetylene (C₂H₂).

16. The method of claim 15, wherein the second source chemical is a metalorganic compound.

17. The method of claim 15, wherein the second source chemical is TMA or TEA.

18. The method of claim 15, wherein the second source chemical is the next source chemical provided after the first metal source chemical.

19. The method of claim 15, wherein the second source chemical is the next source chemical provided after the third source chemical.

20. The method of claim 15, wherein the third source chemical removes some halides from the growing thin film.

21. The method of claim 15, further comprising a second deposition cycle comprising:

contacting the substrate with separate pulses of a first metal source chemical and a second source chemical comprising carbon, wherein no third source chemical is used in the second deposition cycle.

22. The process of claim 21, wherein the second deposition cycle is repeated up to 10 times before performing the first deposition cycle.

23. The method of claim 15, wherein the second source chemical comprises B, Al, In, Sn, Bi, Sn, Zn, Pb, Sb and Ga.

24. 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 first deposition cycles, each first deposition cycle comprising supplying separate pulses of:

a metal halide reactant;

a second reactant comprising water; and

a third reactant that is acetylene (C₂H₂).

25. The method of claim 24, wherein the third reactant removes halides from the growing thin film.

26. The method of claim 24, wherein the metal reactant comprises a metal selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W and Al.

27. The method of claim 24, further comprising a plurality of second deposition cycles, each second deposition cycle comprising supplying separate pulses of:

a metal reactant; and

a second reactant comprising an oxygen source, wherein no third reactant is used in the second deposition cycle.

28. 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 halide source chemical, and a reducing agent selected from the group consisting of boranes and silanes in a first deposition cycle, wherein the deposition enhancing agent is acetylene (C₂H₂).

29. The process of claim 28, wherein the deposition-enhancing agent reacts with halide contaminants in the growing thin film.

30. The method of claim 28, further comprising contacting the substrate with alternating and sequential pulses of a metal source chemical and a reducing agent selected from the group consisting of boranes and silanes in a second deposition cycle, wherein no deposition-enhancing agent is used in the second deposition cycle.

31. 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 WF₆, a silicon source chemical that is a silane (Si_xH_y) and a deposition-enhancing agent that is acetylene (C₂H₂).

32. The process of claim 31, wherein the silicon-containing thin film comprises a metal silicide.

33. The method of claim 31, further comprising a second deposition cycle comprising contacting the substrate with alternating and sequential pulses of a metal source chemical and a silicon source chemical, wherein no deposition-enhancing agent is used in the second deposition cycle.