Treatment apparatus and method for reusing treatment liquid

Patent metadata

Field	Value
Publication number	US-9718710-B2
Application number	US-201514813638-A
Country	US
Kind code	B2
Filing date	Jul 30, 2015
Priority date	Sep 17, 2014
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

According to one embodiment, a treatment apparatus includes a dialysis unit, a treatment unit and a recovery unit. The dialysis unit is configured to dialyze a solution including a phosphoric acid, a silicon compound, and water. The treatment unit is configured to perform treatment of an object to be treated using a dialyzed solution. The recovery unit is configured to recover a solution used in the treatment of the object to be treated and supply to the dialysis unit. The dialysis unit includes a transmission part which allows anions to be transmitted. The recovery unit supplies the solution used in the treatment of the object to be treated, to a region in the dialysis unit. The region is divided by the transmission part.

First claim

What is claimed is:

1. A method for reusing treatment liquid, comprising:
performing treatment of an object to be treated using a first solution including a phosphoric acid and water, said object including a silicon compound;
recovering a second solution used in the treatment of the object to be treated, said second solution including a silicon compound; and
dialyzing the second solution so as to separate the silicon compound from the second solution and producing a third solution including a phosphoric acid and water,
in performing the treatment of the object to be treated, the third solution being added to the first solution.

2. The method according to claim 1 ,
wherein the second solution is dialyzed by electrodialysis or diffusion dialysis.

3. The method according to claim 1 ,
wherein the third solution is added to the first solution after reaching a predetermined concentration.

4. The method according to claim 1 , further comprising heating the third solution.

Assignees

• Toshiba Kk

Inventors

• Hirakawa Masaaki
• Matsui Emi

Classifications

• H10P72/0402 Primary

  Apparatus for fluid treatment (H10P72/0441, H10P72/0448 take precedence) · CPC title

• B01D61/243

  Dialysis · CPC title

• B01D61/44

  Ion-selective electrodialysis · CPC title

• C02F2209/02

  Temperature · CPC title

• C02F2103/346

  from semiconductor processing, e.g. waste water from polishing of wafers · CPC title