Method of plasma enhanced atomic layer deposition of TaC and TaCN films having good adhesion to copper
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.
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 process 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(NC 2 H 5 )(N(C 2 H 5 ) 2 ) 3 , Ta(NC(CH 3 ) 2 C 2 H 5 )(N(CH 3 ) 2 ) 3 , Ta(NC(CH 3 ) 3 )(N(CH 3 ) 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 -C 5 H 5 ) 2 H 3 , Ta(CH 2 )(CH 3 )(η 5 -C 5 H 5 ) 2 , Ta(η 3 -C 3 H 5 )(η 5 -C 5 H 5 ) 2 , Ta(CH 3 ) 3 (η 5 -C 5 H 5) 2 , Ta(CH 3 ) 4 (η 5 -C 5 (CH 3 ) 5 ), or Ta(η 5 -C 5 (CH 3 ) 5 ) 2 H 3 .
9. The method of claim 2 , wherein the second process material comprises as H 2 , NH 3 , N 2 H 4 , NH(CH 3 ) 2 , N 2 H 3 CH 3 , SiH 4 , or Si 2 H 6 , 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, N 2 , or H 2 , or a combination of two or more thereof.
11. The method of claim 2 , wherein step (b) comprises flowing undiluted H 2 gas into the process chamber and exposing said substrate to plasma excited H 2 .
12. The method of claim 2 , wherein step (d) comprises flowing undiluted Argon gas into the process 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) system 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 process chamber of the first process material,
(c) exposing said substrate to a second process material comprising plasma excited H 2 ,
(d) purging said process 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 process 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 H 2 gas into the process chamber and exposing said substrate to plasma excited H 2 .
20. The method of claim 17 , wherein step (f) comprises flowing undiluted Argon gas into the process 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, N 2 , or H 2 , 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).