Deposition of smooth metal nitride films

Patent metadata

Field	Value
Publication number	US-10074541-B2
Application number	US-201715645059-A
Country	US
Kind code	B2
Filing date	Jul 10, 2017
Priority date	Mar 13, 2013
Publication date	Sep 11, 2018
Grant date	Sep 11, 2018

Abstract

In one aspect, methods of forming smooth ternary metal nitride films, such as Ti x W y N z films, are provided. In some embodiments, the films are formed by an ALD process comprising multiple super-cycles, each super-cycle comprising two deposition sub-cycles. In one sub-cycle a metal nitride, such as TiN is deposited, for example from TiCl 4 and NH 3 , and in the other sub-cycle an elemental metal, such as W, is deposited, for example from WF 6 and Si 2 H 6 . The ratio of the numbers of each sub-cycle carried out within each super-cycle can be selected to achieve a film of the desired composition and having desired properties.

First claim

We claim:

1. An atomic layer deposition (ALD) process for depositing a film on a substrate, the process comprising:
alternately and sequentially contacting the substrate with a titanium precursor and a nitrogen reactant; and
alternately and sequentially contacting the substrate with a tungsten precursor and a second precursor,
wherein the second precursor is a silane or borane, and
wherein the film comprises a metal nitride mixture comprising both Ti and W.

2. The process of claim 1 , wherein the titanium precursor is a titanium halide or metal-organic titanium compound and the tungsten precursor is a tungsten halide or metal-organic tungsten compound.

3. The process of claim 1 , wherein the titanium precursor is TiCl 4 and the tungsten precursor is WF 6 .

4. The process of claim 1 , wherein the nitrogen reactant is selected from the group consisting of ammonia, N 2 H 4 , nitrogen atoms, nitrogen containing plasma and nitrogen radicals.

5. The process of claim 1 , wherein the second precursor comprises disilane or trisilane.

6. The process of claim 1 , wherein the compound metal nitride has the formula M 1 x M 2 y N z , wherein x is from 0 to 1.5, y is from 0.05 to 4, z is from 0 to 2, M 1 is Ti and M 2 is W.

7. A method for forming a mixed metal nitride film comprising two different metals M 1 and M 2 on a substrate in a reaction chamber, the method comprising:
a first metal nitride atomic layer deposition (ALD) process comprising:
contacting the substrate with a first vapor-phase metal precursor comprising a first metal M 1 to form at most a molecular monolayer of the metal precursor on the substrate; and
subsequently contacting the substrate with a vapor phase nitrogen reactant to form metal nitride; and

a second elemental metal ALD process comprising:
contacting the substrate with a second vapor phase metal precursor comprising a second metal M 2 different from the first metal; and
subsequently contacting the substrate with a vapor phase second reactant to form elemental metal; and

repeating the first and second ALD processes to form a ternary metal nitride film.

8. The method of claim 7 , wherein the ternary metal nitride has the formula M 1 x M 2 y N z , wherein x is from 0 to 1.5, y is from 0.05 to 4 and z is from 0 to 2.

9. The method of claim 8 , wherein M 1 is Ti and M 2 is W.

10. The method of claim 9 , wherein the first metal precursor is a titanium halide or metal-organic titanium compound and the second metal precursor is a tungsten halide or metal-organic tungsten compound.

11. The method of claim 10 , wherein the titanium precursor is TiCl 4 and the tungsten precursor is WF 6 .

12. The method of claim 7 , wherein the ternary metal nitride film has a roughness of less than 2 nm as measured by x-ray reflectivity.

13. The method of claim 12 , wherein the roughness of less than about 2 nm is at a film thickness of about 20 to about 50 nm.

14. The method of claim 7 , wherein the second elemental metal ALD process is performed before the first metal nitride ALD process.

15. The method of claim 7 , wherein the first metal M 1 is selected from Ti, Ta, Nb, Mo and W and the second metal M 2 is selected from Mo and W.

16. The method of claim 7 , wherein the first metal precursor comprises a metal halide or metal-organic compound.

17. The method of claim 7 , wherein the second metal precursor comprises a metal halide or metal-organic compound.

18. The method of claim 7 , wherein the second reactant comprises a silane or borane.

19. The method of claim 7 , wherein the first ALD process and second ALD process are repeated at a selected ratio.

20. The method of claim 19 , wherein the first ALD process is repeated no more than about 40 times consecutively and the second ALD process is repeated no more than about 10 times consecutively.

Assignees

• Asm Ip Holding Bv

Inventors

• Blomberg Tom E
• Anttila Jaakko

Classifications

• H10D64/01318

  the conductor comprising a layer of alloy material, compound material or organic material contacting the insulator, e.g. TiN (comprising a layer of alloys of Si, Ge or C H10D64/01314) · CPC title

• H10P14/432

  using selective deposition · CPC title

• H10W20/425

  Barrier, adhesion or liner layers · CPC title

• H10W20/033

  in openings in dielectrics · CPC title

• H10W20/062 Primary

  by smoothing of conductive parts, e.g. by planarisation · CPC title