Method of forming a MEOL contact structure

Patent metadata

Field	Value
Publication number	US-12538542-B2
Application number	US-202318196833-A
Country	US
Kind code	B2
Filing date	May 12, 2023
Priority date	May 12, 2023
Publication date	Jan 27, 2026
Grant date	Jan 27, 2026

Abstract

Embodiments of the disclosure include a method of forming contact structure on a semiconductor substrate. The method includes treating a native oxide layer formed on a contact junction, wherein treating the native oxide layer forms a silica salt layer on the contact junction disposed within a contact feature that includes one or more surfaces that comprise silicon nitride. Then exposing the silica salt layer and the one or more surfaces to a plasma comprising oxygen, wherein the plasma forms a silicon oxynitride material on the one or more surfaces. Then removing the second silica salt layer, selectively forming a metal silicide layer on the contact junction, and then filling the contact feature with a metal, wherein filling the feature comprises selectively depositing a metal layer over the selectively formed metal silicide layer.

First claim

What is claimed is:

1 . A method of forming a contact structure on a semiconductor substrate, comprising:
removing material from surfaces of a feature formed in a field region surface of the semiconductor substrate, wherein
removing the material forms a reaction product material over at least one of the field region surface and surfaces within the feature,
the surfaces within the feature comprise sidewalls and a contact surface, and
the surface of the sidewalls comprise silicon nitride;
heating the substrate to a first annealing temperature to remove the reaction product material from the field region surface and the surfaces within the feature; selectively forming a silica salt layer over the contact surface after the reaction product material has been removed from at least the contact surface of the surfaces within the feature; exposing at least portion of the sidewalls and silica salt layer within the feature to a plasma that comprises an oxidizing agent; heating the substrate to a second annealing temperature thereby substantially removing the silica salt layer from the contact surface; forming a metal silicide layer on the contact surface, wherein forming the metal silicide layer on the contact surface comprises selectively depositing a first metal layer on the contact surface; and filling the feature with a metal, wherein filling the feature comprises selectively depositing a second metal layer on the formed metal silicide layer.

2 . The method of claim 1 , wherein exposing at least the portion of the sidewalls forms a silicon oxynitride material on the surface of the sidewalls.

3 . The method of claim 2 , wherein the exposing the at least portion of the sidewalls and silica salt layer within the feature to the plasma further comprises heating the substrate to a third temperature.

4 . The method of claim 3 , wherein forming the metal silicide layer on the contact surface further comprises heating the substrate to a third temperature.

5 . The method of claim 1 , wherein selectively depositing a first metal layer on the contact surface comprises introducing a hydrogen-containing precursor and a first metal-containing precursor to the contact surface such that a first metal layer forms on top of the contact surface that comprises silicon or silicon germanium.

6 . The method of claim 1 , wherein selectively depositing a second metal layer on the formed metal silicide layer comprises introducing a first reducing agent and a second metal-containing precursor to the surface metal silicide layer.

7 . The method of claim 1 , wherein silica salt layer comprises an ammonium hexafluorosilicate.

8 . The method of claim 1 , wherein
the second annealing temperature is different from the first annealing temperature, and the silica salt layer comprises an ammonium hexafluorosilicate.

9 . A method of forming a contact structure on a semiconductor substrate, comprising:
removing material from surfaces of a feature formed in a field region surface of the semiconductor substrate, wherein
removing the material forms a reaction product material over at least one of the field region surface and surfaces within the feature,
the surfaces within the feature comprise sidewalls and a contact surface, and
the surface of the sidewalls comprise silicon;
removing the reaction product material from the field region surface and the surfaces within the feature; selectively forming a silica salt layer over the contact surface after the reaction product material has been removed from at least the contact surface of the surfaces within the feature; exposing at least portion of the sidewalls and silica salt layer within the feature to a plasma that comprises an oxidizing agent; removing the silica salt layer from the contact surface; forming a metal silicide layer on the contact surface, wherein forming the metal silicide layer on the contact surface comprises selectively depositing a first metal layer on the contact surface; and filling the feature with a metal, wherein filling the feature comprises selectively depositing a second metal layer on the formed metal silicide layer.

10 . The method of claim 9 , wherein exposing at least the portion of the sidewalls and silica salt layer within the feature to a plasma forms a silicon oxynitride material on the surface of the sidewalls.

11 . The method of claim 10 , wherein selectively depositing a first metal layer on the contact surface comprises introducing a hydrogen-containing precursor and a first metal-containing precursor to the contact surface such that a first metal layer forms on top of the contact surface that comprises silicon or silicon germanium.

12 . The method of claim 10 , wherein selectively depositing a second metal layer on the formed metal silicide layer comprises introducing a first reducing agent and a second metal-containing precursor to the surface metal silicide layer.

13 . The method of claim 10 , wherein silica salt layer comprises an ammonium hexafluorosilicate.

14 . A method of forming a contact structure on a semiconductor substrate, comprising:
treating an oxide layer formed on a contact junction, wherein
treating the oxide layer forms a first silica salt layer on the contact junction disposed within a contact feature, and
the contact feature comprises one or more surfaces that comprise silicon nitride;
removing the first silica salt layer; forming a second silica salt layer on the contact junction; exposing the second silica salt layer and the one or more surfaces to a plasma comprising oxygen, wherein the plasma forms a silicon oxynitride material on the one or more surfaces; removing the second silica salt layer; selectively forming a metal silicide layer on the contact junction; selectively forming a first metal layer on the selectively formed metal silicide layer; and filling the contact feature with a metal, wherein filling the feature comprises selectively depositing a second metal layer on the selectively formed first metal layer.

15 . The method of claim 14 , wherein selectively forming the first metal layer on the metal silicide layer comprises exposing the contact junction to a non-fluorine-containing precursor.

16 . The method of claim 15 , wherein the non-fluorine-containing precursor comprises tungsten and a chlorine containing gas.

17 . The method of claim 16 , wherein the metal silicide layer comprises titanium.

18 . The method of claim 15 , wherein selectively forming the second metal layer on the first metal layer comprises exposing the contact junction to a fluorine-containing precursor.

19 . The method of claim 14 , wherein silica salt layer comprises an ammonium hexafluorosilicate.

20 . The method of claim 14 , wherein selectively forming the first metal layer on the metal silicide layer comprises exposing the contact junction to a metal precursor that comprises molybdenum (Mo).

Assignees

• Applied Materials Inc

Inventors

• Zhang Shumao
• Zhang Le
• Ye Weifeng
• Hsu Chih-Hsun
• Or David T
• How Gary
• Wan Yiyang
• Wu Liqi
• Lu Jiang

Classifications

• H01L21/28518

  Electricity · mapped topic

• H01L21/76831

  Electricity · mapped topic

• H01L21/02252

  Electricity · mapped topic

• H01L21/0223

  Electricity · mapped topic

• H01L21/0214

  Electricity · mapped topic