Claims
- 1. A method for treating CMP wastewater from a chemical-mechanical polishing process used in chip fabrication, the CMP wastewater containing particles having an abrasive effect and chemically active substances attacking the particles having the abrasive effect, which comprises:removing the particles having the abrasive effect from the CMP wastewater via ultrafiltration in an ultra-filtration facility rapidity enough to ensure that the particles are not substantially dissolved by the chemically active substances present in the wastewater and result in ultrafiltrated wastewater; removing the particles filtered out in the ultra-filtration facility by flushing the particles at a sufficient short intervals so that the particles retained in the ultra-filtration facility are not substantially dissolved by the chemically active substances present in the CMP wastewater; measuring at least one parameter value of the ultrafiltrated wastewater; subjecting the ultrafiltrated wastewater to at least one of a reverse osmosis and nano-filtration process in dependence on a measurement of the at least one parameter value; and collecting a treated product water from said at least one of said reverse osmosis and nanofiltration membrane process.
- 2. The method according to claim 1, which comprises subjecting the ultrafiltrated wastewater to the reverse osmosis.
- 3. The method according to claim 1, which comprises subjecting the ultrafiltrated wastewater to the nano-filtration process.
- 4. The method of claim 1, which further comprises directing the treated water from said at least on of said reverse osmosis and nanofiltration process to a deionization process to produce deionized water.
Priority Claims (1)
Number |
Date |
Country |
Kind |
197 17 865 |
Apr 1997 |
DE |
|
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation of copending International Application PCT/DE98/01164, filed Apr. 27, 1998, which designated the United States.
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Continuations (1)
|
Number |
Date |
Country |
Parent |
PCT/DE98/01164 |
Apr 1998 |
US |
Child |
09/428582 |
|
US |