Depositing ruthenium layers in interconnect metallization

Patent metadata

Field	Value
Publication number	US-10731250-B2
Application number	US-201815996925-A
Country	US
Kind code	B2
Filing date	Jun 4, 2018
Priority date	Jun 6, 2017
Publication date	Aug 4, 2020
Grant date	Aug 4, 2020

Abstract

In some embodiments, deposition processes for ruthenium (Ru) feature fill include deposition of a thin, protective Ru film under reducing conditions, followed by a Ru fill step under oxidizing conditions. The presence of protective Ru films formed under oxygen-free conditions or with an oxygen-removing operation can enable Ru fill without oxidation of an underlying adhesion layer or metal feature.

First claim

What is claimed is:

1. A method comprising:
receiving a substrate including a feature;
performing multiple atomic layer deposition (ALD) cycles to deposit a ruthenium (Ru) liner layer in the feature, wherein each of the ALD cycles include a dose of a reducing agent; and
after depositing the Ru liner layer, at least partially filling the feature with ruthenium by reacting a first ruthenium precursor with an oxidant to form metallic ruthenium (Ru).

2. The method of claim 1 , wherein each of the multiple ALD cycles comprises reacting a second ruthenium precursor with the reducing agent, the second ruthenium precursor being different than the first ruthenium precursor.

3. The method of claim 2 , wherein the first ruthenium precursor has an oxidation state of 0 and the second ruthenium precursor has an oxidation state of +2.

4. The method of claim 1 , wherein each of the multiple ALD cycles include reacting the first ruthenium precursor with the reducing agent.

5. The method of claim 1 , where the feature includes a first liner layer on which the Ru liner is deposited.

6. The method of claim 1 , wherein the ALD cycles are thermal ALD cycles.

7. The method of claim 1 , wherein the ALD cycles are plasma enhanced ALD (PEALD) cycles.

8. The method of claim 1 , wherein the reducing agent is H 2 or NH 3 or plasma species generated from H 2 or NH 3 .

9. The method of claim 1 , wherein the oxidant is O 2 , O 3 , or H 2 O.

10. The method of claim 1 , wherein each of the multiple ALD cycles comprises reacting the first ruthenium precursor with an oxidant.

11. The method of claim 10 , wherein the dose of the reducing agent removes oxygen incorporated into the Ru liner layer or an underlying metallic layer.

12. The method of claim 1 , wherein the feature is fully filled with ruthenium.

13. The method of claim 1 , wherein the feature is fully filled with a metal selected from Ru, Cu, W, Co, Mo, Ni, and Al.

14. The method of claim 1 , wherein each of the multiple ALD cycles comprises a ruthenium precursor dose followed by an oxidant dose.

15. The method of claim 14 , wherein the ruthenium precursor dose and oxidant dose are non-plasma doses.

16. The method of claim 15 , wherein each of the multiple ALD cycles comprises a reducing plasma dose after the oxidant dose.

17. The method of claim 16 , wherein there is no purge between oxidant dose and the reducing plasma dose.

18. The method of claim 14 , wherein the oxidant dose is a mixture of an oxidant and a reducing agent.

19. The method of claim 1 , wherein the Ru liner layer is 2 nm or less.

20. The method of claim 1 , wherein the Ru liner layer is deposited on a layer selected from tungsten carbon nitride (WCN), titanium nitride (TiN), tungsten nitride (WN), tungsten carbide (WC), and tantalum nitride (TaN).

21. The method of claim 1 , wherein the first ruthenium precursor is an organometallic precursor.

22. The method of claim 1 , wherein the first ruthenium precursor has an oxidation state of 0.

23. The method of claim 1 , wherein the first ruthenium precursor has an oxidation state of +2.

24. The method of claim 1 , wherein the first ruthenium precursor is reacted with an oxidant in an ALD process or a CVD process.

25. The method of claim 1 , wherein the Ru liner layer is oxygen-free.

Assignees

• Lam Res Corp

Inventors

• Kim Do Young
• Na Jeong-Seok
• Lai Chiukin Steven
• Humayun Raashina
• Danek Michal

Classifications

• H10P14/6339 Primary

  deposition by cyclic CVD, e.g. ALD, ALE or pulsed CVD · CPC title

• H10P14/6336

  in the presence of a plasma [PECVD] · CPC title

• H10P14/432

  using selective deposition · CPC title

• H10W20/4403

  based on metals, e.g. alloys, metal silicides (H10W20/4484 takes precedence) · CPC title

• H10W20/425

  Barrier, adhesion or liner layers · CPC title