摘要 |
A polishing apparatus (1) has a polishing pad (22), a top ring (20) for holding a semiconductor wafer (W), a vertical movement mechanism (24) operable to move the top ring (20) in a vertical direction, a distance measuring sensor (46) operable to detect a position of the top ring (20) when a lower surface of the top ring (20) is brought into contact with the polishing pad (22), and a controller (47) operable to calculate an optimal position of the top ring (20) to polish the semiconductor wafer (W) based on the position detected by the distance measuring sensor (46). The vertical movement mechanism (24) includes a ball screw mechanism (30, 32, 38, 42) operable to move the top ring (20) to the optimal position. |