| 摘要 |
PROBLEM TO BE SOLVED: To suppress variations in torque fluctuation detection of an electric motor.SOLUTION: A polishing apparatus includes: a first electric motor 14 which rotationally drives a turn table 12; and a second electric motor 22 rotationally driving a top ring 20 which, together with the turn table 12, can hold a workpiece (for example, a semiconductor wafer 18). The turn table 12 and the top ring 20 are rotated while the workpiece is sandwiched therebetween, so that the workpiece is polished and a surface of the workpiece is planarized. At least one of the first electric motor and the second electric motor includes a winding of a plurality of phases. The polishing device further includes: U-phase, V-phase current detecting parts 202, 204 which detect current of at least two phases of the plurality of phases; a three-phase/two-phase converter 220 which generates a composite current based on the detected current; and an endpoint detection device 230 which detects torque fluctuation of the electric motor caused by polishing. |
