Sludge-free treatment of copper CMP wastes
AssigneeAdvanced Micro Devices, Inc.
InventorsLawrence James Dungan, Leon Han
Life of this patent
Estimating the term…
Abstract
Waste slurry containing dissolved metal from e.g., CMP is subjected to sludge-free processing. Embodiments include separating the waste slurry with a solids filter into a solids-free dissolved metal-containing liquid filtrate portion and a concentrated solids-containing portion, removing the dissolved metal from the filtrate by means of an ion exchanger, back-washing the concentrated solids-containing portion with metal-free effluent from the ion exchanger to further reduce its dissolved metal content, discharging the washed concentrated solids-containing portion to a waste drain, removing the metal from the ion exchanger in solution form, and optionally extracting solid metal from the solution by electrowinning.
Claims20
A sludge-free method of treating a waste liquid slurry containing dissolved metal(s), the method comprising the steps of:
- providing a waste treatment system including a solids filter and an ion exchanger;
- supplying the waste liquid slurry containing dissolved metal(s) to the solids filter to separate the slurry into a first, solids-free liquid filtrate portion containing the dissolved metal(s) and a second, concentrated solids-containing waste portion having a substantially reduced dissolved metal(s) concentration;
- passing the first, solid-free liquid filtrate portion through the ion exchanger to substantially remove the dissolved metal(s) and provide a substantially metal(s)-free liquid effluent therefrom;
- washing the second, concentrated solids-containing waste portion in said solids filter by passing therethrough a first portion of the substantially metal(s)-free liquid effluent from the ion exchanger, thereby further reducing the amount of dissolved metal(s) contained therein;
- and
- discharging the washed, concentrated solids-containing waste portion into a waste drain, thereby providing a sludge-free treatment of the waste liquid slurry.
A sludge-free method of treating a dissolved copper-containing waste liquid slurry from a chemical-mechanical polishing (CMP) process, said slurry comprising polishing particles, the method comprising the steps of:
- providing a waste treatment system including a solids filter and an ion exchanger;
- supplying the copper-containing waste liquid slurry to the solids filter to separate the slurry into a first, solids-free liquid filtrate portion containing dissolved copper and a second, concentrated solids-containing waste portion having a substantially reduced dissolved copper concentration;
- passing the first, solids-free liquid filtrate portion through the ion exchanger to substantially remove the dissolved copper and provide a substantially copper-free effluent therefrom;
- washing the second, concentrated solids-containing waste portion in the solids filter by passing therethrough a first portion of the substantially copper-free effluent from the ion exchanger, thereby further reducing the amount of dissolved copper contained therein;
- and
- discharging the washed concentrated solids-containing waste portion into a waste drain, thereby providing a sludge-free treatment of the CMP waste liquid slurry.
A system for sludge-free treatment of a waste liquid slurry containing dissolved metal(s), comprising:
- a solids filter for separating an input stream of said waste liquid slurry into a first, solids-free filtrate portion containing said dissolved metal(s) and a second, concentrated solids-containing waste portion having a substantially reduced dissolved metal(s) concentration;
- an ion exchanger for receiving said first, solids-free liquid filtrate portion containing said dissolved metal(s) and for supplying therefrom substantially metal(s)-free effluent;
- a conduit for supplying a portion of said substantially metal(s)-free effluent from said ion exchanger back to said solids filter for washing the second, concentrated solids-containing portion to further reduce the amount of dissolved metal(s) contained therein;
- and
- an outlet from said solids filter for discharging the washed, concentrated solids-containing portion to a waste drain.
Dependencies are inferred from the claim text.