Tungsten for wordline applications

• US 10,529,722 B2
• Filed: 03/19/2018
• Issued: 01/07/2020
• Est. Priority Date: 02/11/2015
• Status: Active Grant

• Current Assignee: Lam Research Corporation
• Original Assignee: Lam Research Corporation
• Inventors: Danek, Michal, Bamnolker, Hanna, Humayun, Raashina, Gao, Juwen
• Primary Examiner(s): Booth, Richard A
• Application Number:
  US15/925,579
• Publication Number:
  US 20180219014A1
• Time in Patent Office: 659 Days
• CPC Class Codes: C23C 16/0272 Deposition of sub-layers, e.g. to promote the adhesion of the main coating
• CPC Class Codes: C23C 16/08 from metal halides
• CPC Class Codes: C23C 16/30 Deposition of compounds, mixtures or solid solutions, e.g. borides, carbides, nitrides
• CPC Class Codes: H01L 21/28088 the final conductor layer next to the insulator being a composite, e.g. TiN
• CPC Class Codes: H01L 21/28562 Selective deposition
• CPC Class Codes: H01L 21/76843 formed in openings in a dielectric
• 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 23/53257 the principal metal being a refractory metal
• CPC Class Codes: H01L 23/53266 Additional layers associated with refractory-metal layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 29/40117 the electrodes comprising a charge-trapping insulator
• CPC Class Codes: H10B 12/34 the transistor being at least partially in a trench in the substrate
• CPC Class Codes: H10B 12/488 Word lines
• CPC Class Codes: H10B 41/27 the channels comprising vertical portions, e.g. U-shaped channels
• CPC Class Codes: H10B 43/27 the channels comprising vertical portions, e.g. U-shaped channels

Abstract

Disclosed herein are methods and related apparatus for formation of multi-component tungsten-containing films including multi-component tungsten-containing films diffusion barriers. According to various embodiments, the methods involve deposition of multi-component tungsten-containing films using tungsten chloride (WCl_x) precursors and boron (B)-containing, silicon (Si)-containing or germanium (Ge)-containing reducing agents.

Claims

1. A method comprising:

depositing a multi-component tungsten-containing diffusion barrier layer on a dielectric surface of a substrate, wherein depositing the multi-component tungsten-containing diffusion barrier layer comprises exposing the substrate to alternating pulses of a reducing agent and tungsten chloride, wherein the multi-component tungsten-containing diffusion barrier layer comprises between 5% and 60% (atomic) Si; and

depositing a bulk tungsten layer on the multi-component tungsten-containing diffusion barrier layer.

2. The method of claim 1, wherein the between 5% and 60% (atomic) Si is provided by the reducing agent.

3. The method of claim 1, wherein the multi-component tungsten-containing diffusion barrier layer is a ternary or quaternary tungsten-containing film.

4. The method of claim 3, further comprising pulsing a third reactant to form the multi-component tungsten-containing diffusion barrier layer.

5. The method of claim 4, wherein the third reactant is a nitrogen-containing reactant and the multi-component tungsten-containing diffusion barrier layer comprises nitrogen provided by the nitrogen-containing reactant.

6. The method of claim 4, wherein the third reactant is a carbon-containing reactant and the multi-component tungsten-containing diffusion barrier layer comprises nitrogen provided by the carbon-containing reactant.

7. The method of claim 1, wherein the multi-component tungsten-containing diffusion barrier layer is a binary film.

8. The method of claim 1, wherein the substrate temperature during the tungsten chloride pulses is at least 400°

C.

9. The method of claim 1, wherein the substrate temperature during the tungsten chloride pulses is at least 450°

C.

10. The method of claim 1, wherein the substrate temperature during the tungsten chloride pulses is at least 500°

C.

11. The method of claim 1, wherein the substrate temperature during the reducing agent and tungsten chloride pulses is at least 400°

C.

12. The method of claim 1, wherein the substrate temperature during the reducing agent and tungsten chloride pulses is at least 450°

C.

13. The method of claim 1, wherein the substrate temperature during the reducing agent and tungsten chloride pulses is at least 500°

C.

14. The method of claim 1, wherein depositing the bulk tungsten layer comprises a chemical vapor deposition (CVD) reaction between a tungsten chloride precursor and a reducing agent.

15. The method of claim 1, wherein the bulk tungsten layer is deposited directly on the multi-component tungsten-containing diffusion barrier layer without an intervening layer.

16. The method of claim 1, wherein the method further comprises decomposition of the reducing agent to form a layer of B, Si, or Ge on the dielectric surface.

17. The method of claim 1, wherein the multi-component tungsten-containing diffusion barrier layer contains between 15% and 50% (atomic) B, Si, or Ge.

18. The method of claim 1, wherein the multi-component tungsten-containing diffusion barrier layer is selected from the group consisting of quaternary silicon-containing compounds and WSi_xN_y and WSi_xC_y wherein x, y, and z are numbers greater than zero.

19. A method comprising:

depositing a multi-component tungsten-containing diffusion harrier layer on a dielectric surface of a substrate, wherein depositing the multi-component tungsten-containing diffusion barrier layer comprises exposing the substrate to alternating pulses of a reducing agent and tungsten chloride;

wherein the reducing agent is selected from a boron-containing reducing agent, a silicon-containing reducing agent, and germanium-containing reducing agent, wherein the multi-component tungsten-containing diffusion barrier layer is a ternary or quaternary tungsten-containing film and wherein the multi-component tungsten-containing diffusion barrier layer comprises between 5% and 60% (atomic) Si; and

depositing a bulk tungsten layer on the multi-component tungsten-containing diffusion barrier layer.