| 摘要 |
PROBLEM TO BE SOLVED: To reduce dispersion in the polishing rates of semiconductor wafers for every run by controlling a platen rotation speed and a head rotation speed in such a state as increasing/decreasing the relative speed according to the polishing rates of the semiconductor wafers. SOLUTION: The detection result of a polishing rate after completing the polishing is fed back so that a platen rotation speed or a carousel rotation speed, or the both rotation speeds are increased/decreased to the optimal values. A polishing pad 2 is stuck to the whole surface of the platen 1 to polish one side of a semiconductor wafer 5. A drive motor 3 rotates the platen 1 about an axis via a rotary shaft 3a and its rotation speed (platen rotation speed ΩP) is controlled by the platen rotation speed IP. The rotation speed of a head drive motor 7 (head rotation speed ΩH) is controlled by the head rotation command current IH. A control part 10 finds the absolute value of the difference between the film thickness of the semiconductor wafer 5 obtained by the measurement data of the film thickness before the polishing and the film thickness obtained by the measurement data of the film thickness after the polishing as the polishing rate. |
