PURPOSE: To stabilize the quantity of polishing by washing a flat sample after the polishing, drying the washed flat sample, positioning the flat sample, and measuring thickness of the flat sample at the predetermined position, and changing polishing condition on the basis of a result of the measurement.
CONSTITUTION: At the time of polishing a wafer 6, film thickness of the wafer 6 before polishing is measured, and the polishing condition of a polishing surface plate driving unit 24 is set at the initial value by a polishing condition control unit 9. A polishing surface plate 25 is driven by the polishing surface plate driving unit 24 on the basis of this initial value so as to polish the wafer 6, and thereafter, the wafer 6 is carried, and while washed on a wafer receiver table 4. The wafer 6 is held for positioning by a measuring holding unit 23, and film thickness thereof is measured by a film thickness measuring unit 10. The polishing condition control unit 9 subtracts the measured film thickness from the film thickness before polishing so as to compute the quantity of polishing, and judges whether the quantity of polishing exists within the allowable range or not, and in the case where the quantity of polishing exists within the allowable range, the control unit 9 performs the polishing and washing of the next wafer, and in the case where the quantity of polishing exists out of the allowable range, the control unit 9 changes the polishing condition such as the polishing time.
BEPPU TOSHIYASU
SHIBUKI SHUNICHI
