Polishing apparatus

A polishing apparatus for polishing a surface of a workpiece comprising:

• a turntable having a polishing surface;
• a top ring for supporting the workpiece to be polished and pressing the workpiece against said polishing surface;
• and
• a transferring device for transferring the workpiece between said top ring and said transferring device;
• said transferring device comprising:
• a stage having a support surface for supporting the workpiece;
• a first actuating unit for moving said stage in a vertical direction;
• a guide member disposed radially outwardly of said stage and having a guide surface;
• and
• a sensor for detecting a vertical position of said stage;
• wherein when said stage supporting the workpiece is raised toward said top ring to transfer the workpiece to said top ring, said sensor detects whether said stage is raised up to a predetermined position or not.

A method of polishing a surface of a workpiece in a polishing apparatus;

• said polishing apparatus comprising:
• a turntable having a polishing surface;
• a top ring for supporting the workpiece to be polished and pressing the workpiece against said polishing surface, to polish the workpiece;
• and
• a transferring device for transferring the workpiece between said top ring and said transferring device;
• said method comprising;
• transferring the workpiece from said transferring device to said top ring;
• detecting whether the workpiece is held within a predetermined position of said top ring;
• returning the workpiece to said transferring device by removing the workpiece frog said top ring when the workpiece is not held within said predetermined position of said top ring;
• aligning a center of the workpiece with a center of said top ring by said transferring device;
• and
• transferring the workpiece from said transferring device to said top ring.