Method of forming low resistivity fluorine free tungsten film without nucleation

Patent metadata

Field	Value
Publication number	US-9978605-B2
Application number	US-201715398462-A
Country	US
Kind code	B2
Filing date	Jan 4, 2017
Priority date	May 27, 2015
Publication date	May 22, 2018
Grant date	May 22, 2018

Abstract

Provided herein are methods of depositing fluorine-free tungsten by sequential CVD pulses, such as by alternately pulsing a chlorine-containing tungsten precursor and hydrogen in cycles of temporally separated pulses, without depositing a tungsten nucleation layer. Methods also include depositing tungsten directly on a substrate surface using alternating pulses of a chlorine-containing tungsten precursor and hydrogen without treating the substrate surface.

First claim

What is claimed is:

1. A method of filling a feature comprising:
(a) providing a substrate in a chamber, the substrate comprising the feature having an untreated surface comprising a metal; and
(b) without treating the untreated surface of the feature and without depositing a tungsten nucleation layer in the feature, exposing the untreated surface to cycles of alternating pulses of hydrogen and a chlorine-containing tungsten precursor introduced to the chamber to deposit bulk tungsten directly on the untreated surface.

2. The method of claim 1 , wherein the chlorine-containing tungsten precursor is selected from the group consisting of tungsten hexachloride and tungsten pentachloride.

3. The method of claim 1 , wherein a pulse of the chlorine-containing tungsten precursor comprises between about 0.1% and about 1.5% of chlorine-containing tungsten precursor by volume.

4. The method of claim 1 , wherein the chamber is purged between each pulse of the hydrogen and the chlorine-containing tungsten precursor.

5. The method of claim 1 , wherein the bulk tungsten is deposited to a thickness of less than about 50 Å and resistivity of the bulk tungsten is less than about 150 μΩ-cm.

6. A method of filling a feature comprising:
(a) providing a substrate in a chamber, the substrate comprising the feature; and
(b) exposing the substrate to cycles of alternating pulses of hydrogen and a chlorine-containing tungsten precursor introduced to the chamber to deposit bulk tungsten directly in the feature without depositing a tungsten nucleation layer,
wherein pressure of the chamber is no more than 10 Torr.

7. The method of claim 6 , further comprising, (c) prior to exposing the substrate to the alternating pulses of the hydrogen and the chlorine-containing tungsten precursor, exposing the substrate to a reducing agent for a soak treatment.

8. The method of claim 6 , further comprising, (c) prior to exposing the substrate to the alternating pulses of the hydrogen and the chlorine-containing tungsten precursor, exposing the substrate to alternating pulses of a reducing agent and the chlorine-containing tungsten precursor to deposit a tungsten nucleation layer on the substrate.

9. The method of claim 6 , wherein each cycle forms a submonolayer of the bulk tungsten having a thickness of at least about 0.3 Å.

10. The method of claim 6 , wherein the chlorine-containing tungsten precursor is tungsten hexachloride.

11. The method of claim 6 , wherein the chlorine-containing tungsten precursor is tungsten pentachloride.

12. The method of claim 6 , wherein the bulk tungsten is deposited at a substrate temperature between about 400° C. and about 600° C.

13. The method of claim 6 , wherein the chamber is purged between each pulse of the hydrogen and the chlorine-containing tungsten precursor.

14. The method of claim 6 , wherein each purge is performed for a duration between about 0.25 seconds and about 30 seconds.

15. The method of claim 6 , wherein a pulse of the chlorine-containing tungsten precursor comprises between about 0.1% and about 1.5% of chlorine-containing tungsten precursor by volume.

16. The method of claim 6 , wherein the bulk tungsten is deposited to a thickness of less than about 50 Å and resistivity of the bulk tungsten is less than about 150 μΩ-cm.

17. A method of filling a feature comprising:
(a) providing a substrate in a chamber, the substrate comprising the feature, the feature comprising a metal-containing surface;
(b) exposing the metal-containing surface to cycles of alternating pulses of hydrogen and a chlorine-containing tungsten precursor introduced to the chamber to deposit bulk tungsten in the feature without depositing a tungsten nucleation layer; and
(c) prior to exposing the metal-containing surface to the alternating pulses of the hydrogen and the chlorine-containing tungsten precursor, exposing the metal-containing surface to a reducing agent for a soak treatment.

18. The method of claim 17 , wherein a pulse of the chlorine-containing tungsten precursor comprises between about 0.1% and about 1.5% of chlorine-containing tungsten precursor by volume.

19. The method of claim 17 , wherein the bulk tungsten is deposited at a substrate temperature between about 400° C. and about 600° C.

20. The method of claim 17 , wherein the chamber is purged between each pulse of the reducing agent and the chlorine-containing tungsten precursor.

21. The method of claim 17 , wherein each purge is performed for a duration between about 0.25 seconds and about 30 seconds.

22. The method of claim 17 , wherein the reducing agent is selected from the group consisting of germane (GeH 4 ), argon (Ar), tungsten hexafluoride (WF 6 ), diborane (B 2 H 6 ), hydrogen (H 2 ), nitrogen (N 2 ) gas, and combinations thereof.

23. The method of claim 17 , wherein the bulk tungsten is deposited to a thickness of less than about 50 Å and resistivity of the bulk tungsten is less than about 150 μΩ-cm.

Assignees

• Lam Res Corp

Inventors

• Bamnolker Hanna
• Collins Joshua
• Sadilek Tomas
• Shin Hyeong Seop
• Ba Xiaolan
• Humayun Raashina
• Danek Michal
• Schloss Lawrence

Classifications

• H10P14/432

  using selective deposition · CPC title

• 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

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

• H10P14/43 Primary

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