Method of forming low resistivity fluorine free tungsten film without nucleation

• US 9,978,605 B2
• Filed: 01/04/2017
• Issued: 05/22/2018
• Est. Priority Date: 05/27/2015
• Status: Active Grant

• Current Assignee: Lam Research Corporation
• Original Assignee: Lam Research Corporation
• Inventors: Bamnolker, Hanna, Collins, Joshua, Sadilek, Tomas, Shin, Hyeong Seop, Ba, Xiaolan, Humayun, Raashina, Danek, Michal, Schloss, Lawrence
• Primary Examiner(s): Sarkar, Asok K
• Application Number:
  US15/398,462
• Publication Number:
  US 20170117155A1
• Time in Patent Office: 503 Days
• Field of Search: None
• CPC Class Codes: C23C 16/0281 of metallic sub-layers C23C16/029 takes precedence
• CPC Class Codes: C23C 16/045 Coating cavities or hollow spaces, e.g. interior of tubes; Infiltration of porous substrates
• CPC Class Codes: C23C 16/14 Deposition of only one other metal element
• CPC Class Codes: C23C 16/455 characterised by the method used for introducing gases into reaction chamber or for modifying gas flows in reaction chamber
• CPC Class Codes: C23C 16/45523 Pulsed gas flow or change of composition over time
• CPC Class Codes: C23C 16/458 characterised by the method used for supporting substrates in the reaction chamber
• CPC Class Codes: C23C 16/52 Controlling or regulating the coating process C23C16/45557, C23C16/279 take precedence
• CPC Class Codes: H01L 21/28556 by chemical means, e.g. CVD, LPCVD, PECVD, laser CVD H01L21/28518 - H01L21/28537 and H01L21/28568 take precedence
• CPC Class Codes: H01L 21/28562 Selective deposition
• CPC Class Codes: H01L 21/28568 the conductive layers comprising transition metals H01L21/28518 takes precedence
• CPC Class Codes: H01L 21/76876 for deposition from the gas phase, e.g. CVD
• CPC Class Codes: H01L 21/76877 Filling of holes, grooves or trenches, e.g. vias, with conductive material
• CPC Class Codes: H01L 28/00 Passive two-terminal components without a potential-jump or surface barrier for integrated circuits; Details thereof; Multistep manufacturing processes therefor testing or measuring during manufacture H01L22/00; integration methods H01L21/70; integrated circuits H01L27/00; two-terminal components with a potential-jump or surface barrier H01L29/00; resistors in general H01C; inductors in general H01F; capacitors in general H01G
• CPC Class Codes: H10B 43/27 the channels comprising vertical portions, e.g. U-shaped channels

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.

Claims

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 μ

Ω

-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 μ

Ω

-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 (GeH₄), argon (Ar), tungsten hexafluoride (WF₆), diborane (B₂H₆), hydrogen (H₂), nitrogen (N₂) 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 μ

Ω

-cm.