Abrasive liquid feed apparatus, method for feeding additive to abrasive liquid feed apparatus, and polishing apparatus

摘要

An abrasive liquid feed apparatus comprises a supply tank for storing an abrasive liquid having a predetermined concentration, an abrasive liquid pipe for transferring the abrasive liquid from the tank to a polishing means and an additive feed means which feeds an additive having a predetermined concentration to the tank. It further comprises an additive concentration measurement means which measures a concentration of the additive in the abrasive liquid in the supply tank, a measurement means which measures an amount of the abrasive liquid in the tank and a control which calculates an amount of the additive to be supplemented to the tank, based on the concentration of the additive measured by the additive concentration measurement means and the amount of the abrasive liquid measured by the metering means. To maintain the concentration of aqueous hydrogen peroxide in the abrasive liquid.