Method of plasma enhanced atomic layer deposition of TaC and TaCN films having good adhesion to copper

• US 20070218670A1
• Filed: 03/20/2006
• Published: 09/20/2007
• Est. Priority Date: 03/20/2006
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Ishizaka, Tadahiro
• Granted Patent: US 7,407,876 B2
• Time in Patent Office: Days
• US Class Current: 438/597
• CPC Class Codes: C23C 16/32 Carbides
• CPC Class Codes: C23C 16/36 Carbonitrides
• CPC Class Codes: C23C 16/4554 Plasma being used non-continuously in between ALD reactions C23C16/56 takes precedence
• CPC Class Codes: C23C 16/5096 Flat-bed apparatus
• CPC Class Codes: H01L 21/28562 Selective deposition
• CPC Class Codes: H01L 21/76843 formed in openings in a dielectric

Abstract

A method for processing a substrate for forming TaC and TaCN films having good adhesion to Cu. The method includes disposing the substrate in a process chamber of a plasma enhanced atomic layer deposition (PEALD) system configured to perform a PEALD process, and depositing a TaC or TaCN film on the substrate using the PEALD process. The PEALD process includes (a) exposing the substrate to a first process material containing tantalum, (b) exposing the substrate to a second process material containing a plasma excited reducing agent, (c) repeating steps (a) (b) a predetermined number of times, (d) exposing the substrate to plasma excited Argon, and (e) repeating steps (c) and (d) until the TaC or TaCN film has a desired thickness. Preferably, purging of the process chamber is performed after one or more of the exposing steps.

Claims

1. A method for processing a substrate comprising:

disposing said substrate in a process chamber of a plasma enhanced atomic layer deposition (PEALD) system configured to perform a PEALD process; and

depositing a TaC or TaCN film on said substrate using said PEALD process, wherein the depositing comprises;

a) exposing said substrate to a first process material comprising tantalum;

b) exposing said substrate to a second process material comprising a plasma excited reducing agent,

c) repeating steps (a) and (b) a predetermined number of times,

d) after step (c) exposing the substrate to plasma excited Argon, and

e) repeating steps (c) and (d) until the TaC or TaCN film has a desired thickness.

2. The method of claim 1, further comprising purging said PEALD chamber after each of steps (a) and (b).

3. The method of claim 2, wherein said predetermined number is between 2 and 100 times.

4. The method of claim 2, wherein said predetermined number is between 30 and 70 times.

5. The method of claim 2, wherein step (e) is performed between 1 and 100 times

6. The method of claim 2, wherein step (e) is performed between 10 and 20 times.

7. The method of claim 2, wherein the depositing comprises depositing a TaCN film and the first process material comprises TAIMATA, PDEAT, PEMAT, PDMAT, TBTDET, Ta(NC₂H₅)(N(C₂H₅)₂)₃, Ta(NC(CH₃)₂C₂H₅)(N(CH₃)₂)₃, Ta(NC(CH₃)₃)(N(CH₃)₂)₃, or TBTEMAT.

8. The method of claim 2, wherein the depositing comprises depositing a TaC film and the first process material comprises Ta(η

⁵-C₅H₅)₂H₃, Ta(CH₂)(CH₃)(η

⁵-C₅H₅)₂, Ta(η

³-C₃H₅) (η

⁵-C₅H₅)₂, Ta(CH₃)₃(η

⁵-C₅H₅)₂, Ta(CH₃)₄(η

⁵-C₅(CH₃)₅), or Ta(η

⁵-C₅(CH₃)₅)₂H₃.

9. The method of claim 2, wherein the second process material comprises as H₂, NH₃, N₂H₄, NH(CH₃)₂, N₂H₃CH₃, SiH₄, or Si₂H₆, or a combination of two or more thereof.

10. The method of claim 2, wherein the purging steps comprise flowing a purge gas through the process chamber, wherein the purge gas comprises a noble gas, N₂, or H₂, or a combination of two or more thereof

11. The method of claim 2, wherein step (b) comprises flowing undiluted H₂ gas into the PEALD chamber and exposing said substrate to plasma excited H₂.

12. The method of claim 2, wherein step (d) comprises flowing undiluted Argon gas into the PEALD chamber and exposing said substrate to the plasma excited Argon.

13. The method of claim 2, wherein at least one of steps (b) and (d) comprise applying substrate holder bias.

14. The method of claim 13, wherein the substrate holder bias is between 100 and 2000 W.

15. The method of claim 13, wherein the substrate holder bias is between 100 and 500 W.

16. The method of claim 2, wherein step (a) is performed in the absence of a plasma.

17. A method for processing a substrate comprising:

disposing said substrate in a process chamber of a plasma enhanced atomic layer deposition (PEALD) chamber configured to perform a PEALD process; and

depositing a TaCN film on said substrate using said PEALD process, wherein the depositing comprises;

a) exposing said substrate to a first process material comprising TAIMATA,

b) purging said PEALD chamber of the first process material,

c) exposing said substrate to a second process material comprising plasma excited H₂,

d) purging said PEALD chamber of the second process material,

e) repeating steps (a)-(d) a predetermined number of times,

f) exposing the substrate to plasma excited Argon, and

(g) repeating steps (a)-(f) until the TaCN film has a desired thickness.

18. The method of claim 17, wherein step (a) comprises flowing undiluted TAIMATA gas into the PEALD chamber and exposing said substrate to TAIMATA in the absence of a plasma.

19. The method of claim 17, wherein step (c) comprises flowing undiluted H₂ gas into the PEALD chamber and exposing said substrate to plasma excited H₂.

20. The method of claim 17, wherein step (f) comprises flowing undiluted Argon gas into the PEALD chamber and exposing said substrate to the plasma excited Argon.

21. The method of claim 17, wherein the purging steps (b) and (d) comprise flowing a purge gas through the process chamber, wherein the purge gas comprises a noble gas, N₂, or H₂, or a combination of two or more thereof.

22. The method of claim 17, wherein steps (a)-(d) are performed between 2 and 100 times.

23. The method of claim 17, wherein steps (a)-(f) are performed between 1 and 100 times.

24. The method of claim 17, wherein at least one of steps (c) and (f) comprise applying substrate holder bias.

25. The method of claim 17, wherein the substrate holder bias is between 100 and 500 W.

26. The method of claim 17, wherein the substrate holder bias is between 100 and 2000 W.

27. The method of claim 17, wherein the substrate is maintained at a temperature of 240°

C. or less in step (a).