摘要 |
Wastewater from a chemical-mechanical polishing process (CMP) used in semiconductor chip fabrication has hitherto been, and is still being, discharged into the public sewage system after chemical neutralization and sedimentation. This has the drawback that water consumption is considerable. It is therefore an object of the invention to reduce the total amount of wastewater produced that has to be discharged. This is achieved by the wastewater to be treated being subjected to an ultra-filtration. This allows the treated CMP wastewater to be reused within the plant. In particular, it can be recycled in order again to recover therefrom deionized water of a very high purity for operational purposes, e.g. for CMP.
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