Atomic layer deposition of metallic contacts, gates and diffusion barriers
View Patent ↗The present invention provides metallic films containing a Group IVB or VB metal, silicon and optionally nitrogen by utilizing atomic layer deposition (ALD). In particularly, the present invention provides a low temperature thermal ALD method of forming metallic silicides and a plasma-enhanced atomic layer deposition (PE-ALD) method of forming metallic silicon nitride film. The methods of the present invention are capable of forming metallic films having a thickness of a monolayer or less on the surface of a substrate. The metallic films provided in the present invention can be used for contact metallization, metal gates or as a diffusion barrier.
1. A method of forming a metallic silicide film comprising:
first exposing a substrate to a first flux of a Group IVB or VB metal precursor to form a condensed and absorbed monolayer or less of said metal precursor on a surface of the substrate; and
second exposing the condensed and absorbed monolayer or less to a second flux of a silicon source to provide a metal silicide film having a graded composition, wherein said first and second exposing is performed at a substrate temperature of less than 450° C.
2. The method of claim 1 wherein the metal precursor is a halogen-containing Group IVB or VB compound of the formula MX a wherein M is a Group IVB or VB metal, a is 4 or 5, and X is a halogen.
3. The method of claim 1 wherein the metal precursor is TaCl 5 .
4. The method of claim 1 wherein the silicon source is a silane of the formula Si n H 2n+2 wherein n is from 1 to 10.
5. The method of claim 4 wherein the silane is SiH 4 .
6. The method of claim 1 further comprising introducing a hydrogen plasma to said substrate prior to said second exposing.
7. The method of claim 1 further comprising introducing a hydrogen plasma to said substrate after said second exposing.
8. The method of claim 1 wherein after each exposing step a purge gas is introduced to said substrate.
9. The method of claim 1 wherein said first exposing comprises TaCl 5 and said second exposing comprises SiH 4 .
10. The method of claim 1 wherein an evacuation step occurs between the first and second exposing.
11. A method of forming a metallic silicide film comprising:
first exposing a substrate to a first flux of a Group IVB or VB metal precursor to form a condensed and absorbed monolayer or less of said metal precursor on a surface of the substrate;
introducing a hydrogen plasma to said substrate containing said metal precursor after said first exposing; and
second exposing the condensed and absorbed monolayer or less to a second flux of a silicon source to provide a metal silicide film, wherein said first and second exposing is performed at a substrate temperature of less than 450° C.
12. The method of claim 11 wherein the metal precursor is a halogen-containing Group IVB or VB compound of the formula MX a wherein M is a Group IVB or VB metal, a is 4 or 5, and X is a halogen.
13. The method of claim 11 wherein the metal precursor is TaCl 5 .
14. The method of claim 11 wherein the silicon source is a silane of the formula Si n H 2n+2 wherein n from 1 to 10.
15. The method of claim 14 wherein the silane is SiH 4 .
16. The method of claim 11 wherein after each exposing step a purge gas is introduced to said substrate.
17. The method of claim 11 wherein said first exposing comprises TaCl 5 and said second exposing comprises SiH 4 .
18. The method of claim 11 wherein the metal silicide film has a graded composition.
19. A method of forming a metallic silicide film comprising the steps of:
first exposing a substrate to a first flux of a Group IVB or VB metal precursor to form a condensed and absorbed monolayer or less of said metal precursor on a surface of the substrate;
second exposing the condensed and absorbed monolayer or less to a second flux of a silicon source, wherein said first and second exposing is performed at a substrate temperature of less than 450° C.; and
introducing a hydrogen plasma to said substrate after said second exposing.
20. The method of claim 19 wherein the metal precursor is a halogen-containing Group IVB or VB compound of the formula MX a wherein M is a Group IVB or VB metal, a is 4 or 5, and X is a halogen.
21. The method of claim 19 wherein the metal precursor is TaCl 5 .
22. The method of claim 19 wherein the silicon source is a silane of the formula Si n H 2n+2 wherein n is from 1 to 10.
23. The method of claim 22 wherein the silane is SiH 4 .
24. The method of claim 19 wherein after each exposing step a purge gas is introduced to said substrate.
25. The method of claim 19 wherein said first exposing comprises TaCl 5 and said second exposing comprises SiH 4 .
26. The method of claim 19 wherein the metal silicide has a graded composition.