Method of forming a metal carbide or metal carbonitride film having improved adhesion

• US 7,645,484 B2
• Filed: 03/31/2006
• Issued: 01/12/2010
• Est. Priority Date: 03/31/2006
• Status: Expired due to Fees

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Ishizaka, Tadahiro
• Primary Examiner(s): Meeks; Timothy H
• Assistant Examiner(s): BURKHART, ELIZABETH A
• Application Number:
  US11/393,872
• Publication Number:
  US 20070231487A1
• Time in Patent Office: 1,383 Days
• Field of Search: 427/248.1, 427/249.1, 427/569, 427/228, 42724917-24919
• US Class Current: 427/249.17
• CPC Class Codes: C23C 16/32 Carbides
• CPC Class Codes: C23C 16/36 Carbonitrides
• 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 16/45565 Shower nozzles
• CPC Class Codes: C23C 16/45574 Nozzles for more than one gas
• CPC Class Codes: C23C 16/5096 Flat-bed apparatus

Abstract

A method for forming a metal carbide or metal carbonitride film on a substrate using a vapor deposition process. The method includes comprises introducing a first process material, such as a film precursor, to the substrate followed by introducing a second process material, such as a film reducing agent, to the substrate, whereby plasma can be formed during the introduction of the second process material in order to assist reduction of the first process material on the substrate. Additionally, the temperature of the substrate is elevated to a value approximately equal to or greater than the decomposition temperature of the first process material in order to improve adhesion properties for the metal carbide or metal carbonitride film.

Claims

1. A method of depositing a thin film on a substrate, having a feature formed thereon, using a vapor deposition process, comprising:

identifying a degree of step coverage required for the thin film on the feature based on a process performed on the substrate, a product to be produced from the substrate or both the process performed and the product produced;

disposing said substrate in a processing chamber configured to facilitate said vapor deposition process;

forming a metal carbide or metal carbonitride film on said substrate by performing one or more vapor deposition process cycles, each process cycle comprising;

exposing said substrate to a first process material within said processing chamber;

after the exposing the substrate to the first process material, introducing a purge gas to said processing chamber to purge the processing chamber of the first process material;

after the introducing the purge gas, exposing said substrate to a second process material within said processing chamber; and

generating a local plasma in said processing chamber during said exposing of said substrate to said second process material; and

after the performing the one or more vapor deposition process cycles, elevating a temperature of said substrate during the forming step to a value greater than a decomposition temperature of said first process material but less than a temperature at which the identified degree of step coverage cannot be achieved and performing one or more additional vapor deposition process cycles at the elevated temperature in order to improve adhesion properties for said metal carbide or metal carbonitride film by altering the carbon content therein.

2. The method of claim 1, wherein said forming comprises forming a metal carbide or metal carbonitride film having Ta, Ti, or W therein.

3. The method of claim 1, wherein said forming comprises forming a TaC or TaCN film.

4. The method of claim 3, wherein said exposing said substrate to said first process material comprises exposing said substrate to Ta(NC(CH₃)₂C₂H₅)(N(CH₃)₂)₃.

5. The method of claim 4, wherein said elevating comprises elevating the temperature of said substrate to a decomposition temperature of 253 degrees C. or greater but less than said temperature at which the identified degree of step coverage cannot be achieved.

6. The method of claim 5, wherein said elevating comprises elevating the temperature of said substrate to 300 degrees C. or greater but less than said temperature at which the identified degree of step coverage cannot be achieved.

7. The method of claim 6, wherein said elevating comprises elevating the temperature of said substrate to approximately 340 degrees C. or greater but less than said temperature at which the identified degree of step coverage cannot be achieved.

8. The method of claim 4, wherein:

said forming comprises forming a TaCN film on the substrate,

said exposing said substrate to said first process material comprises exposing the substrate to a gas flow of 90 mg/mm of Ta(NC(CH₃)₂C₂H₅)(N(CH₃)₂)₃, 200 sccm of Argon carrier gas and 500 scorn of Argon 10 for a period of 5 seconds,

said exposing said substrate to said second process material comprises exposing the substrate to 2000 scorn of H₂ for a period of 20 seconds,

said generating a plasma comprises generating a local plasma local to the substrate.

9. The method of claim 3, wherein said elevating comprises elevating the temperature of said substrate to a value where the ratio of the amount of C to the amount of Ta in said TaC or TaCN film measured using X-ray fluorescence (XRF) spectroscopy exceeds a value of approximately 0.1475.

10. The method of claim 9, wherein said elevating comprises elevating the temperature of said substrate to a value where the ratio of the amount of C to the amount of Ta in said TaC or TaCN film measured using X-ray fluorescence spectroscopy exceeds a value of approximately 0.15.

11. The method of claim 10, wherein said elevating comprises elevating the temperature of said substrate to a value where the ratio of the amount of C to the amount of Ta in said TaC or TaCN film measured using X-ray fluorescence spectroscopy exceeds a value of approximately 0.1525.

12. The method of claim 9, wherein said elevating comprises elevating the temperature of said substrate to a value where a ratio of the amount of C to the amount of Ta in said TaC or TaCN film measured using X-ray fluorescence (XRF) spectroscopy is from 0.1475 to 0.1525.

13. The method of claim 1, wherein said exposing said substrate to said first process material comprises exposing said substrate to a tantalum containing material including one or more of Ta[N(C₂H₅CH₃)]₅ (PEMAT), Ta[N(CH₃)₂]₅ (PDMAT), Ta[N(C₂H₅)₂]₅ (PDEAT), Ta(NC(CH₃)₃)(N(C₂H₅)₂)₃ (TBTDET), Ta(NC₂H₅)(N(C₂H₅)₂)₃, Ta(NC(CH₃)₂C₂H₅)(N(CH₃)₂)₃, or Ta(NC(CH₃)₃)(N(CH₃)₂)₃.

14. The method of claim 1, wherein said exposing said substrate to a second process material comprises exposing said substrate to a process material comprising at least one of H₂, N₂, O₂, H₂O, NH₃, H₂O₂, SiH₄, or SiH₆.

15. The method of claim 1, wherein said generating plasma comprises coupling electromagnetic power to at least one of a plasma electrode and a substrate holder of the processing chamber.

16. The method of claim 1, further comprising exposing said substrate to at least one of said first and second process materials using a carrier gas.

17. The method of claim 1, wherein said introducing the purge gas comprises introducing an inert gas to said processing chamber.

18. The method of claim 1, further comprising following one or more of said one or more vapor deposition process cycles, exposing said substrate to plasma formed from a noble gas.

19. The method of claim 18, wherein said exposing said substrate to plasma formed from a noble gas comprises exposing said substrate to an argon plasma.

20. The method of claim 1, wherein said forming a metal carbide or metal carbonitride film comprises performing one or more vapor deposition process cycles using plasma formed at a first power level and performing one or more vapor deposition process cycles using plasma formed at a second power level different from said first power level.

21. The method of claim 1, wherein said elevating comprises changing said temperature of the substrate from below said vapor decomposition temperature to above the vapor decomposition temperature during said forming step.

22. The method of claim 1, wherein said forming comprises forming a barrier or seed layer, or a combination thereof on the feature of a substrate.

23. The method of claim 1, wherein said forming comprises maintaining a temperature of the substrate at a first value below a decomposition temperature for a portion of the forming, and maintaining a temperature of the substrate at a second value above a decomposition temperature for another portion of the forming.

24. The method of claim 1, wherein said elevating comprises maintaining said temperature at said value during an entire duration of the forming step.

25. The method of claim 1, wherein said forming comprises forming the film in a pure ALD regime during initial deposition of the film to obtain initial conformality, and then performing said elevating to form the film in a CVD regime to achieve improved adhesion.