High purity tin and method for manufacturing same

Patent metadata

Field	Value
Publication number	US-2018298506-A1
Application number	US-201615574039-A
Country	US
Kind code	A1
Filing date	Oct 12, 2016
Priority date	Oct 19, 2015
Publication date	Oct 18, 2018
Grant date	—

Abstract

Provided is a high purity tin (Sn) having an extremely low oxygen content. A high purity tin having a tin purity of 5N (99.999% by mass, provided that carbon, nitrogen, oxygen and hydrogen are excluded) or more, wherein the high purity tin has an oxygen content of less than 10 ppb by mass, as measured by elemental analysis using Dynamic-SIMS.

First claim

1 . A high purity tin having a tin purity of 5N (99.999% by mass, provided that carbon, nitrogen, oxygen and hydrogen are excluded) or more, wherein the high purity tin has an oxygen content of less than 10 ppb by mass, as measured by elemental analysis using Dynamic-SIMS.

2 . The high purity tin according to claim 1 , wherein the high purity tin has a sulfur content of less than 0.1 ppm by mass, as measured by elemental analysis using GD-MS.

3 . The high purity tin according to claim 1 , wherein the sulfur content is less than 0.01 ppm by mass, as measured by elemental analysis using GD-MS.

4 . The high purity tin according to claim 1 , wherein the high purity tin has a carbon content of less than 10 ppb by mass, as measured by elemental analysis using Dynamic-SIMS.

5 . A method for manufacturing a high purity tin, comprising subjecting tin having a purity of 3N (99.9% by mass, provided that carbon, nitrogen, oxygen and hydrogen are excluded) or more, and having an oxygen content of 5 ppm by mass or more and a carbon content of 10 ppm by mass or more as measured by elemental analysis using a nondispersive infrared absorption method, to a vacuum heating treatment until the oxygen content in the tin is decreased to be less than 10 ppb by mass as measured by elemental analysis using Dynamic-SIMS.

6 . The method according to claim 5 , wherein the vacuum heating treatment is carried out at a temperature of 400° C. or more and a degree of vacuum higher than 1×10 −3 Pa (absolute pressure).

7 . The method according to claim 5 , wherein the vacuum heating treatment is carried out for 3 hours or more.

8 . The method according to claim 5 , further comprising electrolytically refining a raw material tin using an electrolytic solution containing at least one carbon-containing compound to obtain the tin having the purity of 3N (99.9% by mass, provided that carbon, nitrogen, oxygen and hydrogen are excluded) or more, and having the oxygen content of 5 ppm by mass or more and the carbon content of 10 ppm by mass or more as measured by elemental analysis using the nondispersive infrared absorption method, wherein the raw material tin has a purity of 3N (99.9% by mass, provided that carbon, nitrogen, oxygen and hydrogen are excluded) or more, and has an oxygen content of 5 ppm by mass or more and a carbon content of less than 10 ppm by mass, as measured by elemental analysis using a nondispersive infrared absorption method.

9 . The method according to claim 8 , wherein the at least one carbon-containing compound is a leveling agent.

10 . The method according to claim 5 , further comprising adding elemental carbon to a raw material tin to obtain the tin having the purity of 3N (99.9% by mass, provided that carbon, nitrogen, oxygen and hydrogen are excluded) or more, and having the oxygen content of 5 ppm by mass or more and the carbon content of 10 ppm by mass or more as measured by elemental analysis using the nondispersive infrared absorption method, wherein the raw material tin has a purity of 3N (99.9% by mass, provided that carbon, nitrogen, oxygen and hydrogen are excluded) or more, and has an oxygen content of 5 ppm by mass or more and a carbon content of less than 10 ppm by mass, as measured by elemental analysis using a nondispersive infrared absorption method.

11 . The method according to claim 5 , wherein carbon atom is present at a ratio of 1 mole or more and 500 mole or less per 1 mole of oxygen atom in the tin having the purity of 3N (99.9% by mass, provided that carbon, nitrogen, oxygen and hydrogen are excluded) or more, and having the oxygen content of 5 ppm by mass or more and the carbon content of 10 ppm by mass or more as measured by elemental analysis using the nondispersive infrared absorption method.

12 . The method according to claim 5 , wherein carbon atom is present at a ratio of 50 mole or more and 100 mole or less per 1 mole of oxygen atom in the tin having the purity of 3N (99.9% by mass, provided that carbon, nitrogen, oxygen and hydrogen are excluded) or more, and having the oxygen content of 5 ppm by mass or more and the carbon content of 10 ppm by mass or more as measured by elemental analysis using the nondispersive infrared absorption method.

13 . A tin target material comprising the high purity tin according to claim 1 , used for generating EUV light in a lithographic EUV light source.

Assignees

• Jx Nippon Mining & Metals Corp

Inventors

• Imori Toru
• Takemoto Kouichi

Classifications

• C22B9/04

  Refining by applying a vacuum · CPC title

• G03F7/70008

  Production of exposure light, i.e. light sources · CPC title

• C22B25/08

  Refining · CPC title

• C25C1/14 Primary

  of tin · CPC title

• H05G2/0035

  the material containing metals as principal radiation-generating components · CPC title