| 摘要 |
A polishing apparatus has a polishing table ( 12 ) with a polishing surface ( 10 ) attached thereon, and a top ring ( 20 ) for pressing a workpiece (W) against the polishing surface ( 10 ). The top ring ( 20 ) has a housing ( 40 ) and a retainer ring ( 44 ) vertically movable in the housing ( 40 ) for holding an outer circumferential edge of the workpiece (W). The polishing apparatus includes a vertically moving mechanism operable to vertically move the top ring ( 20 ), a bracket ( 28 ) vertically movable together with the top ring ( 20 ), a stopper ( 32 ) adjustable in vertical position to prevent downward movement of the bracket ( 28 ), and a sensor ( 36 ) for detecting a distance between the stopper ( 32 ) and the bracket ( 28 ). The polishing apparatus also includes a control unit ( 34 ) operable to adjust the stopper ( 32 ) in vertical position based on the distance signal from the sensor ( 36 ). |
