Patent ID: 6955764
Filing Date: 2005-10-18
Classification: B01F,B24B,G05D

Abstract:
1. An apparatus for preparing a slurry for a CMP apparatus, comprising: a slurry tank for preparing the slurry; a weight sensor adapted for measuring the weight of the slurry tank; a stock solution feeder for the slurry which feeds a stock solution for the slurry into the slurry tank; and a concentration sensor which is located in a closed loop pipe having an inlet end for drawing the slurry from the slurry tank and an outlet end for returning the slurry back into the slurry tank, and which is outside the slurry tank and adapted to measure an additive concentration in the slurry in the tank, wherein the additive concentration in the slurry in the slurry tank is measured by the concentration sensor, the weight of the slurry tank is measured by the weight sensor and an amount of the stock solution for the slurry to be supplied is controlled according to the measured additive concentration and measured weight of the slurry tank.