Polishing apparatus and semiconductor manufacturing method

A polishing apparatus comprising:

• a first polishing part;
• a second polishing part comprising a mounting surface for a semiconductor substrate, and rubbing the semiconductor substrate mounted on the mounting surface while pressing the semiconductor substrate against the first polishing part;
• and
• an annular part comprising a support part provided in the second polishing part, and a plurality of convex portions that project from the support part toward the first polishing part, are arranged in a circumferential direction around the mounting surface while being supported by the support part, and are movable in a radial direction of the semiconductor substrate, wherein
• the annular part comprises a first moving part moving the convex portions in the radial direction, and
• the first moving part changes the location of each of the convex portions in a direction in which an inner diameter of the annular part is reduced or increased in a state where each of the convex portions is in contact with the first polishing part, wherein
• the first moving part comprises
• a plurality of slits provided in the support part to face the convex portions, respectively, and to be inclined to a radial direction toward a same direction as a rotation direction of the second polishing part when the second polishing part rubs the semiconductor substrate along with movement in a radially outward direction, and
• a plurality of pins inserted to an inside of the support part through the slits and supported by the support part to be slidable along the slits, respectively.