Methods of etching films comprising transition metals

Patent metadata

Field	Value
Publication number	US-9390940-B2
Application number	US-201414206474-A
Country	US
Kind code	B2
Filing date	Mar 12, 2014
Priority date	Mar 13, 2013
Publication date	Jul 12, 2016
Grant date	Jul 12, 2016

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.

First claim

What is claimed is:

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 H 2 , NO, N 2 O, NF 3 , Cl 2 , Ar or N 2 .

6. The method of claim 5 , wherein the plasma comprises N 2 O, and exposure of the substrate surface to the N 2 O 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 O 2 , O 3 , N 2 O, NO, Br 2 , F 2 , I 2 or Cl 2 .

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.

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.

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

wherein each R a is independently hydrogen or C1-C4 alkyl, with the proviso that not all of the R a groups are hydrogen.

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.

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 Br 2 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.

Assignees

• Applied Materials Inc

Inventors

• Anthis Jeffrey W
• Schmiege Benjamin
• Thompson David

Classifications

• H10P50/266 Primary

  by vapour etching only · CPC title

• H10P50/267 Primary

  using plasmas · CPC title

• H01L21/32135 Primary

  Electricity · mapped topic

• H01J37/32862

  In situ cleaning of vessels and/or internal parts · CPC title

• H01L21/32136

  Electricity · mapped topic