Methods of etching films comprising transition metals

• US 9,390,940 B2
• Filed: 03/12/2014
• Issued: 07/12/2016
• Est. Priority Date: 03/13/2013
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Anthis, Jeffrey W., Schmiege, Benjamin, Thompson, David
• Primary Examiner(s): Lu, Jiong-Ping
• Application Number:
  US14/206,474
• Publication Number:
  US 20140273492A1
• Time in Patent Office: 853 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: C23F 1/00 Etching metallic material by chemical means manufacture of printing surfaces B41C; manufacture of printed circuits H05K
• CPC Class Codes: C23F 1/12 Gaseous compositions
• CPC Class Codes: C23F 4/00 Processes for removing metallic material from surfaces, not provided for in group C23F1/00 or C23F3/00
• CPC Class Codes: H01J 37/32715 Workpiece holder
• CPC Class Codes: H01J 37/32862 In situ cleaning of vessels and/or internal parts
• CPC Class Codes: H01L 21/32135 by vapour etching only
• CPC Class Codes: H01L 21/32136 using plasmas

Abstract

Provided are methods for etching films comprising transition metals. Certain methods involve activating a substrate surface comprising at least one transition metal, wherein activation of the substrate surface comprises exposing the substrate surface to heat, a plasma, an oxidizing environment, or a halide transfer agent to provide an activated substrate surface; and exposing the activated substrate surface to a reagent comprising a Lewis base or pi acid to provide a vapor phase coordination complex comprising one or more atoms of the transition metal coordinated to one or more ligands from the reagent. Certain other methods provide selective etching from a multi-layer substrate comprising two or more of a layer of Co, a layer of Cu and a layer of Ni.

Claims

1. A method of etching a substrate, the method comprising:

activating a substrate surface comprising a transition metal, wherein activation of the substrate surface comprises exposing the substrate surface to heat, a plasma, an oxidizing environment, or a halide transfer agent to provide an activated substrate surface; and

exposing the activated substrate surface to a reagent comprising a Lewis base or pi acid to provide a vapor phase coordination complex comprising one or more atoms of the transition metal coordinated to one or more ligands from the reagent

wherein the Lewis base or pi acid comprises a chelating amine selected from the group consisting of N,N,N′

,N′

-tetramethylethylene diamine, ethylene diamine, N,N′

-dimethylethylenediamine, 2-(aminomethyl)pyridine, 2- [(alkylamino)methyl]pyridine, and 2-[(dialkylamino)methyl]pyridine, wherein the alkyl group is C1-C6 alkyl.

2. The method of claim 1, wherein activation of the substrate surface comprises exposing the substrate surface to heat.

3. The method of claim 2, wherein exposure of the substrate surface to heat and the reagent occur sequentially or substantially sequentially.

4. The method of claim 1, wherein activation of the substrate surface comprises exposing the substrate surface to a plasma.

5. The method of claim 4, wherein the plasma comprises H₂, NO, N₂O, NF₃, Cl₂, Ar or N₂.

6. The method of claim 5, wherein the plasma comprises N₂O, and exposure of the substrate surface to the N₂O results in a —

NO surface termination.

7. The method of claim 1, wherein activation of the substrate surface comprises exposure to a halide transfer agent.

8. The method of claim 1, wherein exposure of the substrate surface to an oxidizing environment comprises exposing the substrate surface to O₂, O₃, N₂O, NO, Br₂, F₂, I₂ or Cl₂.

9. The method of claim 1, wherein the substrate surface comprises about 90 to about 100% transition metal and 0 to about 10% carbon.

10. The method of claim 1, wherein the substrate surface overlies a deposition chamber wall or showerhead.

11. The method of claim 1, wherein the transition metal comprises an element selected from the group consisting of Co, Ru, Ni, Fe, Mn and Pd.

14. The method of claim 10, wherein the chelating amine has a structure represented by:

15. The method of claim 14, wherein the chelating amine is selected from the group consisting of N,N,N′

,N′

-tetramethylethylene diamine and N,N′

-dimethylethylenediamine.

16. The method of claim 15, further comprising purging the coordination complex.

12. A method of etching a multi-layer substrate, the method comprising:

providing a multi-layer substrate comprising two or more of a layer of Co, a layer of Cu and a layer of Ni;

activating a surface of the layer of Co, layer of Cu or layer of Ni, wherein activation of the substrate surface comprises exposing the substrate surface to heat, a plasma or a halide transfer agent to provide an activated substrate surface; and

exposing the activated substrate surface to a chelating amine at a first temperature such that the chelating amine will only form a volatile metal coordination complex with one of Co, Cu or Ni at the first temperature.

13. The method of claim 12, further comprising exposing the activated substrate surface to a chelating amine at a second temperature, such that the chelating amine will only form a volatile metal coordination complex with one of Co, Cu or Ni at the second temperature.

17. A method of etching a substrate, the method comprising:

activating a substrate surface comprising cobalt or copper, wherein activation of the substrate surface comprises exposing the substrate surface to Br₂ to provide an activated substrate surface; and

exposing the activated substrate surface to a reagent comprising TMEDA to provide a vapor phase coordination complex comprising one or more atoms of the cobalt or copper coordinated to one or more ligands from the reagent.