Stainless steel member and production method thereof

Patent metadata

Field	Value
Publication number	US-2021001303-A1
Application number	US-201916976842-A
Country	US
Kind code	A1
Filing date	Feb 25, 2019
Priority date	Mar 2, 2018
Publication date	Jan 7, 2021
Grant date	—

Abstract

The purpose of the present invention is to provide a stainless steel member and a production method thereof, said stainless steel member having a passivation layer formed on a surface of a base material formed from stainless steel, wherein the film thickness of the passivation layer is 2-20 nm, and the concentration of chromium atoms in the outermost surface of the passivation layer is 0.1-2.3 by atomic percentage. Also provided are a device or container, the liquid-contact part of which in contact with a semiconductor treatment liquid is formed from the stainless steel member, a semiconductor treatment liquid production method for producing the semiconductor treatment liquid by using the device, and a semiconductor treatment liquid storage method for storing the semiconductor treatment liquid in the container.

First claim

1 . An austenite stainless steel member comprising:
a base material made of austenite stainless steel; and a passivation layer formed on a surface of the base material made of austenite stainless steel, wherein the passivation layer has a thickness of 2 nm to 20 nm, a concentration of chromium atoms in an outermost surface of the passivation layer is 0.1 atomic % to 1.0 atomic %, and a concentration of silicon atoms in the outermost surface of the passivation layer is 2 atomic % to 10 atomic %.

2 . The austenite stainless steel member according to claim 1 which is for use in a part to be in contact with a semiconductor treatment liquid.

3 . (canceled)

4 . The austenite stainless steel member according to claim 1 , wherein the passivation layer has a thickness of 3 nm to 20 nm.

5 . An apparatus having a part to be in contact with a semiconductor treatment liquid, wherein the part comprises the austenite stainless steel member according to claim 1 .

6 . A method of producing a semiconductor treatment liquid, the method comprising:
using the apparatus according to claim 5 in producing a semiconductor treatment liquid.

7 . A method of storing a semiconductor treatment liquid, the method comprising:
storing the semiconductor treatment liquid in a container comprising the austenite stainless steel member according to claim 1 .

8 . A method of producing the austenite stainless steel member according to claim 1 , the method comprising:
forming the passivation layer by electropolishing, rinsing with inorganic acid, and heating, wherein the heating is performed at a temperature of 300° C. to 450° C. in an oxidizing atmosphere.

9 . (canceled)

10 . The apparatus according to claim 5 , which is a reaction tank, distillation column, stirrer, transport pipe, or storage tank for use in a semiconductor treatment liquid producing process.

11 . A container having a part to be in contact with a semiconductor treatment liquid, wherein the part comprises the austenite stainless steel member according to claim 1 .

Assignees

• Tokuyama Corp

Inventors

• Sera Akira
• Nakatani Michihito
• Nakamura Yumiko

Classifications

• C25F3/24 Primary

  of iron or steel · CPC title

• C23F17/00

  Multi-step processes for surface treatment of metallic material involving at least one process provided for in class C23 and at least one process covered by subclass C21D or C22F or class C25 (coating for obtaining at least two superposed coatings either by methods not provided for in a single one of main groups C23C2/00 - C23C26/00, or by combinations of methods providedfor in subclasses C23C and C25D, C23C28/00) · CPC title

• C23G1/085

  solutions containing HNO3 · CPC title

• C23C22/74

  for obtaining burned-in conversion coatings · CPC title

• C23C22/50

  Treatment of iron or alloys based thereon · CPC title