Polishing apparatus for flattening surface of workpiece

摘要

To provide a polishing apparatus capable of more accurately determining a polishing end point. The polishing apparatus includes a turntable 12, a first electric motor 14 configured to rotationally drive the turntable, a top ring 20 configured to hold a workpiece together with the turntable, and a second electric motor 22 configured to rotationally drive the top ring. The polishing apparatus further includes a weighting unit configured to perform weighting so as to make the current ratios of the respective phases different from each other, and a torque variation detecting unit configured to detect a change in a phase current greatly weighted by the weighting unit and thereby detects a change in torque of the electric motor, the change being generated by performing the polishing.

主权项

1. A polishing apparatus for flattening a surface of a workpiece, the polishing apparatus comprising:
a polishing table; a first electric motor configured to rotationally drive the polishing table; a substrate holding unit configured to hold the workpiece; a second electric motor configured to rotationally drive the substrate holding unit, at least one of the first and second electric motors having a plurality of phase windings; a weighting unit configured to make currents of the plurality of phase windings different from each other; and a torque variation detecting unit configured to detect a change in a current made by the weighting unit and thereby detect a change in torque of the at least one of the first and second electric motors, the change being generated by performing a polishing of the workpiece.