Protective fluid for alumina, protection method, and production method for semiconductor substrate having alumina layer using same

Patent metadata

Field	Value
Publication number	US-12338381-B2
Application number	US-201916976565-A
Country	US
Kind code	B2
Filing date	Feb 27, 2019
Priority date	Mar 2, 2018
Publication date	Jun 24, 2025
Grant date	Jun 24, 2025

Abstract

The present invention pertains to a protective fluid for alumina, a protection method, and a production method for semiconductor substrate having an alumina layer using same. This alumina protective fluid is characterized by: containing 0.0001%-20% by mass of an alkali earth metal compound; and the alkali earth metal being at least one selected from the group consisting of beryllium, magnesium, strontium, and barium. As a result of the present invention, alumina corrosion can be suppressed during the production process for semiconductor circuits.

First claim

The invention claimed is:

1. A method for protecting alumina, the method comprising:
treating at least a portion of a surface of an alumina layer comprising alumina with a protective fluid consisting of (i) water and (ii) barium nitrate, barium acetate, and/or barium chloride in a range of from more than 1 to 20 wt. % together, based on total protective fluid weight, to thereby form a fluid film on the portion of the surface of the alumina layer; and
washing over the fluid film and the alumina layer with an optionally corrosive washing solution,
wherein the treating is at a temperature in a range of from 30 to 60° C. for a time in a range of from 0.2 to less than 60 minutes.

2. A method for producing a semiconductor substrate having an alumina layer, the method comprising:
protecting alumina comprised in the alumina layer using the method of claim 1 .

3. A method for producing a semiconductor substrate having an alumina layer, the method comprising:
protecting alumina comprised in the alumina layer by treating the alumina layer with the protective fluid consisting of (i) water and (ii) barium nitrate, barium acetate, and/or barium chloride in a range of from more than 1 to 20 wt. % together, based on total protective fluid weight, to thereby form a fluid film on the portion of the surface of the alumina layer; and
washing over the fluid film and the alumina layer with an optionally corrosive washing solution,
wherein the treating is at a temperature in a range of from 30 to 60° C. for a time in a range of from 0.2 to less than 60 minutes.

4. The method of claim 1 , wherein the alumina is in an alumina layer.

5. The method of claim 1 , wherein the barium nitrate is present in the protective fluid.

6. The method of claim 2 , wherein the barium nitrate is present in the protective fluid.

7. The method of claim 3 , wherein the barium nitrate is present in the protective fluid.

8. The method of claim 1 , wherein the barium acetate is present in the protective fluid.

9. The method of claim 2 , wherein the barium acetate is present in the protective fluid.

10. The method of claim 3 , wherein the barium acetate is present in the protective fluid.

11. The method of claim 1 , wherein the barium chloride is present in the protective fluid.

12. The method of claim 2 , wherein the barium chloride is present in the protective fluid.

13. The method of claim 3 , wherein the barium chloride is present in the protective fluid.

14. The method of claim 1 , wherein the barium nitrate, the barium acetate, and/or the barium chloride are present in the protective fluid is from 1.5 to 10% by mass.

15. The method of claim 2 , wherein the barium nitrate, the barium acetate, and/or the barium chloride are present in the protective fluid is from 1.5 to 10% by mass.

16. The method of claim 3 , wherein the barium nitrate, the barium acetate, and/or the barium chloride are present in the protective fluid is from 1.5 to 10% by mass.

17. The method of claim 1 , wherein the barium nitrate, the barium acetate, and the barium chloride are present in the protective fluid.

18. The method of claim 1 , wherein the barium nitrate, the barium acetate, and/or the barium chloride, together, are present in the protective fluid in a range of from 1 to 2% by mass.

19. The method of claim 1 , wherein the treating is at a temperature in a range of from 30 to 55° C.

20. The method of claim 1 , wherein the treating is at a temperature in a range of from 40 to 55° C.

Assignees

• Mitsubishi Gas Chemical Co

Inventors

• OIE Toshiyuki
• Putra Priangga Perdana
• HORITA Akinobu

Classifications

• H10P70/23 Primary

  during, before or after processing of insulating materials · CPC title

• H10W20/074

  of dielectric parts comprising thin functional dielectric layers, e.g. dielectric etch-stop, barrier, capping or liner layers · CPC title

• H10P50/242

  of Group IV materials · CPC title

• H10D64/01332

  Making the insulator · CPC title

• H10P76/405

  characterised by their composition, e.g. multilayer masks · CPC title