To reduce the consumption of the slurry and rinsing water of a CMP device without seriously damaging a polished workpiece, and reduce the manufacture cost of the device.
Recycled slurry is uninterruptedly mixed with slurry in use, and a stable polishing rate is thereby attained. A part of the slurry continuously flowing across a polishing pad 11 is consumed or discarded. The remaining slurry is collected into a catch ring 23, sent to a recycle loop and mixed with new slurry, a regenerative chemical substance or water. A mixture so prepared is tested and filtrated before returned to the polishing pad 11. In this case, the volume of the slurry returned to the pad 11 is slightly larger than the volume collected, and causes an overflow from the catch ring 23. Rinsing water is similarly recycled to keep the polishing pad 11 in a wet state between polishing cycles.
KRULIK GERALD A
HARWOOD C RANDALL
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