Nucleation-free tungsten deposition

Patent metadata

Field	Value
Publication number	US-12237221-B2
Application number	US-202017595590-A
Country	US
Kind code	B2
Filing date	May 18, 2020
Priority date	May 22, 2019
Publication date	Feb 25, 2025
Grant date	Feb 25, 2025

Abstract

Provided herein are methods of depositing tungsten (W) films without depositing a nucleation layer. In certain embodiments, the methods involve depositing a conformal reducing agent layer of boron (B) and/or silicon (Si) on a substrate. The substrate generally includes a feature to be filled with tungsten with the reducing agent layer conformal to the topography of the substrate including the feature. The reducing agent layer is then exposed to a fluorine-containing tungsten precursor, which is reduced by the reducing agent layer to form a layer of elemental tungsten. The conformal reducing agent layer is converted to a conformal tungsten layer.

First claim

What is claimed is:

1. A method comprising:
depositing an elemental tungsten bulk layer without depositing a tungsten nucleation layer on a surface of a substrate by:
forming a layer comprising elemental boron (B) on the surface; and
after forming the layer, performing multiple cycles of exposing the substrate to alternating pulses of a tungsten fluoride compound and hydrogen (H 2 ) to thereby form the elemental tungsten bulk layer on the surface.

2. The method of claim 1 , wherein a B content at an interface of the elemental tungsten bulk layer and the surface is no more than 10 21 atoms/cm 3 .

3. The method of claim 1 , wherein a B content at an interface of the elemental tungsten bulk layer and the surface is no more than 5×10 20 atoms/cm 3 .

4. The method of claim 1 , wherein a B content at an interface of the elemental tungsten bulk layer and the surface is no more than 2×10 20 atoms/cm 3 .

5. The method of claim 1 , wherein the layer comprising elemental boron is between 10 and 50 Angstroms thick.

6. The method of claim 1 , wherein the layer comprising elemental boron is less than 30 Angstroms thick.

7. The method of claim 1 , wherein the layer comprising elemental boron consists essentially of boron.

8. The method of claim 1 , wherein the layer comprising elemental boron further comprises silicon.

9. The method of claim 1 , wherein the surface is a nitride surface.

10. The method of claim 1 , wherein the surface is a titanium nitride surface.

11. The method of claim 1 , wherein the surface is an oxide surface.

12. The method of claim 1 , wherein forming the layer comprising elemental boron comprises exposing the surface to diborane.

13. The method of claim 1 , wherein forming the layer comprising elemental boron comprises exposing the surface to diborane and silane.

14. The method of claim 1 , wherein a chamber pressure of a chamber housing the substrate during the forming a layer comprising elemental boron (B) is between 10 Torr and 90 Torr.

15. The method of claim 1 , wherein the forming a layer comprising elemental boron (B) and the performing multiple cycles are performed in a same chamber.

16. The method of claim 15 , comprising lowering a chamber pressure after forming the layer comprising elemental boron and prior to performing the multiple cycles.

17. The method of claim 1 , wherein forming the layer comprising elemental boron (B) on the surface comprises exposing the surface to a gas mixture comprising boron (B) and silicon (Si) wherein a B:Si ratio is between 1:1 and 6:1.

18. The method of claim 17 , wherein the gas mixture comprises diborane and silane.

19. The method of claim 1 , wherein the forming the layer comprising elemental boron (B) on the surface comprises thermal decomposition of a boron-containing reducing agent without adsorption of the boron-containing reducing agent on the surface.

20. The method of claim 1 , wherein the layer of elemental boron conforms to a topography of the surface.

Assignees

• Lam Res Corp

Inventors

• Ermez Sema
• Deng Ruopeng
• Nishioka Yutaka
• Ba Xiaolan
• Gopinath Sanjay
• Danek Michal

Classifications

• H10P14/418

  the conductive layers comprising transition metals · CPC title

• H10W20/056

  by filling conductive material into holes, grooves or trenches · CPC title

• H10W20/045 Primary

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

• H10W20/031

  of conductive parts of the interconnections · CPC title

• H10P14/432

  using selective deposition · CPC title