METHOD OF SILICON EXTRACTION USING A HYDROGEN PLASMA

• US 20170345667A1
• Filed: 05/26/2017
• Published: 11/30/2017
• Est. Priority Date: 05/29/2016
• Status: Abandoned Application

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Sherpa, Sonam D., Ranjan, Alok
• Application Number:
  US15/607,359
• Publication Number:
  US 20170345667A1
• Time in Patent Office: Days
• CPC Class Codes: H01L 21/0337 characterised by the process involved to create the mask, e.g. lift-off masks, sidewalls, or to modify the mask, e.g. pre-treatment, post-treatment
• CPC Class Codes: H01L 21/3065 Plasma etching; Reactive-ion etching
• CPC Class Codes: H01L 21/32137 of silicon-containing layers

Abstract

A method of silicon extraction using a hydrogen plasma has been disclosed in various embodiments. The substrate processing method includes providing a substrate containing a first material consisting of silicon and a second material that is different from the first material, forming a plasma-excited process gas containing H₂ and optionally Ar, and exposing the substrate to the plasma-excited process gas to selectively etch the first material relative to the second material. According to one embodiment, the second material is selected from the group consisting of SiN, SiO₂, and a combination thereof.

Claims

1. A substrate processing method, comprising:

providing a substrate containing a first material consisting of elemental Si and a second material that is different from the first material;

forming a plasma-excited process gas containing H₂ and optionally Ar; and

exposing the substrate to the plasma-excited process gas to selectively etch the first material relative to the second material.

2. The method of claim 1, wherein the process gas consists of H₂.

3. The method of claim 1, wherein the process gas consists of H₂ and Ar.

4. The method of claim 1, wherein the second material is selected from the group consisting of SiN, SiO₂, and a combination thereof.

5. The method of claim 1, wherein the second material includes an organic material.

6. The method of claim 1, wherein the first material includes raised features on the substrate, the second material forms sidewall spacers on vertical portions of the raised features, and the exposing removes the raised features of the first material but not the sidewall spacers.

7. The method of claim 6, wherein the second material is selected from the group consisting of SiN and SiO₂.

8. The method of claim 6, wherein the first and second materials are direct contact with an underlying SiO₂ material, and the second material includes SiN.

9. The method of claim 1, wherein forming the plasma-excited process gas includes generating a plasma using a capacitively coupled plasma source containing an upper plate electrode, and a lower plate electrode supporting the substrate.

10. The method of claim 1, wherein forming the plasma-excited process gas includes generating a plasma using a remote plasma source that creates a high radical to ion flux ratio.

11. A substrate processing method, comprising:

providing a substrate containing a first material consisting of elemental Si and a second material selected from the group consisting of SiN, SiO₂, and a combination thereof;

forming a plasma-excited process gas consisting of H₂ and Ar; and

exposing the substrate to the plasma-excited process gas to selectively etch the first material relative to the second material.

12. The method of claim 11, wherein the first material includes raised features on the substrate, the second material forms sidewall spacers on the vertical portions of the raised features, and wherein the exposing removes the raised features of the first material but not the sidewall spacers.

13. The method of claim 11, wherein forming the plasma-excited process gas includes generating a plasma using a capacitively coupled plasma source containing an upper plate electrode, and a lower plate electrode supporting the substrate.

14. The method of claim 11, wherein forming the plasma-excited process gas includes generating a plasma using a remote plasma source that creates a high radical to ion flux ratio.

15. A substrate processing method, comprising:

providing a substrate containing a first material that includes raised features on the substrate, a second material that forms sidewall spacers on vertical portions of the raised features, wherein the first and second materials are in direct contact with an underlying third material, the first material consisting of elemental Si, the second material consisting of SiN, and the third material consisting of SiO₂;

forming a plasma-excited process gas consisting of H₂ and optionally Ar; and

exposing the substrate to the plasma-excited process gas to selectively remove the first material relative to the second material and the third material.

16. The method of claim 15, wherein forming the plasma-excited process gas includes generating a plasma using a capacitively coupled plasma source containing an upper plate electrode, and a lower plate electrode supporting the substrate.

17. The method of claim 15, wherein forming the plasma-excited process gas includes generating a plasma using a remote plasma source that creates a high radical to ion flux ratio.

18. The method of claim 15, wherein the process gas consists of H₂.

19. The method of claim 15, wherein the process gas consists of H₂ and Ar.