Ruthenium metal feature fill for interconnects

Patent metadata

Field	Value
Publication number	US-10056328-B2
Application number	US-201715651979-A
Country	US
Kind code	B2
Filing date	Jul 17, 2017
Priority date	Jun 5, 2015
Publication date	Aug 21, 2018
Grant date	Aug 21, 2018

Abstract

A method is provided for at least partially filling a feature in a substrate. The method includes providing a substrate containing a feature, depositing a ruthenium (Ru) metal layer to at least partially fill the feature, and heat-treating the substrate to reflow the Ru metal layer in the feature.

First claim

What is claimed is:

1. A method for at least partially filling a feature in a substrate, the method comprising:
providing a substrate containing a feature;
depositing a ruthenium (Ru) metal layer to at least partially fill the feature; and
heat-treating the substrate to reflow the Ru metal layer in the feature,
wherein the Ru metal layer is deposited at a first substrate temperature and the heat-treating is performed at a second substrate temperature between 200° C. and 600° C. that is greater than the first substrate temperature.

2. The method of claim 1 , further comprising:
prior to depositing the Ru metal layer, forming a nucleation layer in the feature.

3. The method of claim 2 , wherein the nucleation layer is selected from the group consisting of Mo, MoN, Ta, TaN, W, WN, Ti, and TiN.

4. The method of claim 1 , wherein the Ru metal layer is deposited by atomic layer deposition (ALD), chemical vapor deposition (CVD), plating, or sputtering.

5. The method of claim 4 , wherein the Ru metal layer is deposited by CVD using Ru 3 (CO) 12 and CO carrier gas.

6. The method of claim 1 , wherein the substrate includes a dielectric layer and the feature is formed in the dielectric layer.

7. The method of claim 1 , wherein the heat-treating is performed in the presence Ar gas, H 2 gas, Ar gas and H 2 gas, or H 2 gas and N 2 gas.

8. The method of claim 1 , wherein the second substrate temperature is between 400° C. and 500° C.

9. A method for filling a feature in a substrate, the method comprising:
providing a substrate containing a feature;
depositing a conformal ruthenium (Ru) metal layer that fills the feature; and
heat-treating the substrate to reflow the conformal Ru metal layer in the feature,
wherein the conformal Ru metal layer has seam voids in the feature and the heat-treating seals the seam voids and increases the grain size of the conformal Ru metal layer in the feature, and
wherein the conformal Ru metal layer is deposited at a first substrate temperature and the heat-treating is performed at a second substrate temperature between 200° C. and 600° C. that is greater than the first substrate temperature.

10. The method of claim 9 , wherein the second substrate temperature is between 400° C. and 500° C.

11. The method of claim 9 , wherein the substrate includes a dielectric layer and the feature is formed in the dielectric layer.

12. The method of claim 9 , further comprising:
prior to depositing the conformal Ru metal layer, forming a nucleation layer in the feature.

13. The method of claim 12 , wherein the nucleation layer is selected from the group consisting of Mo, MoN, Ta, TaN, W, WN, Ti, and TiN.

14. The method of claim 9 , wherein the conformal Ru metal layer is deposited by atomic layer deposition (ALD), chemical vapor deposition (CVD), plating, or sputtering.

15. The method of claim 9 , wherein the conformal Ru metal layer is deposited by CVD using Ru 3 (CO) 12 and CO carrier gas.

16. The method of claim 9 , wherein the heat-treating is performed in the presence Ar gas, H 2 gas, Ar gas and H 2 gas, or H 2 gas and N 2 gas.

17. A method for at least partially filling a feature in a substrate, the method comprising:
providing a substrate containing a feature;
depositing a ruthenium (Ru) metal layer to at least partially fill the feature, wherein depositing the Ru metal layer pinches off a feature opening before the feature is filled with the Ru metal layer, thereby forming a void inside the feature;
removing excess Ru metal that caused the pinch off; and
thereafter, depositing additional Ru metal in the feature, wherein the Ru metal layer and the additional Ru metal are deposited by CVD using Ru 3 (CO) 12 and CO carrier gas.

18. The method of claim 17 , further comprising:
prior to depositing the Ru metal layer, forming a nucleation layer in the feature, wherein the nucleation layer is selected from the group consisting of Mo, MoN, Ta, TaN, W, WN, Ti, and TiN.

19. The method of claim 17 , wherein the removing the excess Ru metal includes a planarization process.

Assignees

• Tokyo Electron Ltd

Inventors

• Yu Kai-Hung
• Leusink Gerrit J
• Wajda Cory
• Ishizaka Tadahiro
• HAKAMATA Takahiro

Classifications

• H10P14/432

  using selective deposition · CPC title

• H10P14/43

  Chemical deposition, e.g. chemical vapour deposition [CVD] · CPC title

• H10W20/045

  for deposition from the gaseous phase, e.g. for chemical vapour deposition [CVD] · CPC title

• H10W20/4432

  the principal metal being a noble metal, e.g. gold · CPC title

• H10W20/096

  by contacting with gases, liquids or plasmas · CPC title