Patent ID: 7666063
Filing Date: 2010-02-23
Classification: H01L

Abstract:
1. A polishing apparatus of a semiconductor wafer for polishing a semiconductor wafer, comprising: a polishing table rotated by a drive current and provided with a polishing pad; a slurry-supplying unit for supplying polishing slurry to the polishing table; a controller for controlling the polishing table and the slurry-supplying unit, the semiconductor wafer being pressed onto the polishing table and being polished by the slurry supplied by the slurry-supplying unit; an alkali-concentrate-solution supplying unit for supplying an alkali concentrate solution to the polishing table; a deionized-water supplying unit for supplying deionized water to the polishing table; a flow-regulating valve that adjusts the flow rate of the alkali concentrate solution from the alkali-concentrate-solution supplying unit; and a drive current detecting unit that detects the drive current to the polishing table, the controller comprising: a load current calculating unit that calculates a load current generated on the polishing table while polishing using the slurry based on the drive current detected by the drive current detecting unit; a pH value determining unit that determines, based on the calculated load current, a pH value of an alkali solution supplied from the flow-regulating valve to the polishing table, the alkali solution being prepared by mixing the alkali concentrate solution and the deionized water, and a flow control unit for controlling the flow rate of the flow-regulating valve based on the determined pH value.