The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 02, 2019
Filed:
Dec. 07, 2015
Applicant:
Kurita Water Industries Ltd., Tokyo, JP;
Inventors:
Hideyuki Komori, Tokyo, JP;
Nobuhiro Orita, Tokyo, JP;
Assignee:
KURITA WATER INDUSTRIES LTD., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01L 21/306 (2006.01); B01D 61/02 (2006.01); B01D 61/12 (2006.01); B01D 61/14 (2006.01); B01D 61/22 (2006.01); B01D 61/58 (2006.01); C02F 1/52 (2006.01); C02F 103/34 (2006.01); C02F 11/12 (2006.01); C02F 1/66 (2006.01);
U.S. Cl.
CPC ...
H01L 21/30604 (2013.01); B01D 61/12 (2013.01); B01D 61/22 (2013.01); B01D 61/58 (2013.01); B01D 61/027 (2013.01); B01D 61/145 (2013.01); B01D 2311/06 (2013.01); C02F 1/52 (2013.01); C02F 1/66 (2013.01); C02F 11/12 (2013.01); C02F 2001/5218 (2013.01); C02F 2103/346 (2013.01); Y02W 10/37 (2015.05);
Abstract
A method for treating an etching solution in order to circulate and reuse an etching solution used in etching treatment of silicon includes (1) selectively removing multivalent ions having a valence of two or more, or (2) removing multivalent ions having a valence of two or more, 20-50% of alkali metal ions having a valence of one relative to a total amount of the alkali metal ions, and hydroxide ions, through a membrane separation unit comprising a nanofiltration membrane. A permeated solution of the membrane separation unit is circulated to the etching bath.