Polishing apparatus and semiconductor manufacturing method

1. 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.

2. The apparatus of claim 1 , wherein the first moving part moves each of the convex portions in a radially inward direction when the second polishing part rotates in a same direction as when the second polishing part rubs the semiconductor substrate, and moves each of the convex portions in a radially outward direction when the second polishing part rotates in an opposite direction to when the second polishing part rubs the semiconductor substrate.

3. The apparatus of claim 1 , wherein the convex portions respectively comprise a side surface along an outer circumferential surface of the semiconductor substrate.

4. The apparatus of claim 1 , further comprising:

an attaching/detaching part comprising a guide part guiding attachment and detachment of the semiconductor substrate to/from the second polishing part, and attaching and detaching the semiconductor substrate to/from the second polishing part while the convex portions are in contact with the guide part, wherein

the guide part is rotatable in the circumferential direction, and

the first moving part moves each of the convex portions according to rotation of the guide part in a state where each of the convex portions is in contact with the guide part.

5. The apparatus of claim 4 , wherein the first moving part moves each of the convex portions in a radially inward direction when the guide part rotates in an opposite direction to a rotation direction of the second polishing part when the second polishing part rubs the semiconductor substrate, and moves each of the convex portions in a radially outward direction when the guide part rotates in a same direction as the rotation direction of the second polishing part when the second polishing part rubs the semiconductor substrate.

6. The apparatus of claim 5 , wherein

the attaching/detaching part comprises a controller controlling rotation of the guide part, and

the controller executes control of stopping rotation of the guide part when the convex portions move in the radially inward direction and come into contact with an outer circumferential surface of the semiconductor substrate.

7. The apparatus of claim 1 , wherein

each of the pins comprises a first stopper preventing falling of a corresponding one of the convex portions inside the support part,

the support part comprises a second stopper facing top end portions of the pins inside the support part and regulating upward movement of the convex portions by contact with the top end portions of the pins, and

the top end portions of the pins and the second stopper are elastic.