To provide a polishing device and a method thereof which are capable of measuring the thickness of a film on the polished surface of a work as an object of polishing with high accuracy and preventing the surface of the work from being locally and excessively polished.
The polishing device is equipped with a top ring 30 holding a work W as an object of polishing and a polishing base with a polishing surface 10a. The work W as the object of polishing is made to slide on the polishing surface 10a for polishing as a polishing solution is applied on the polishing surface 10a. The polishing device is equipped with moving mechanisms 38, 40, 42, and 44 which move the top ring 30 to enable a part of the work W to protrude from the peripheral edge of the polishing surface 10a, an image recognizing unit 50 for measuring the thickness of a film on the polished surface of the work W, and a cleaning unit 56 which is provided on the upper side of the image recognizing unit 50 in the rotative direction of the work W and cleans the polishing solution attached on the polished surface of the work W as the object of polishing.
Shintaro Hotta
Ryoji Kosugi
Tomohiro Mori