Polishing apparatus
A polishing apparatus is used for polishing a substrate such as a semiconductor wafer to a flat mirror finish. The polishing apparatus includes a polishing table ( 100 ) having a polishing surface ( 101 a ), a top ring body ( 2 ) configured to hold and press a substrate against the polishing surface ( 101 a ), and a retainer ring ( 3 ) provided at an outer peripheral portion of the top ring body ( 2 ) and configured to press the polishing surface ( 101 a ). A fulcrum for receiving a lateral force applied from the substrate to the retainer ring ( 3 ) during polishing of the substrate is located above a central portion of the substrate.
1. An apparatus for polishing a substrate, comprising:
a polishing table having a polishing surface;
a top ring body having a pressure chamber for being supplied with a pressurized fluid and configured to press the substrate against said polishing surface under a fluid pressure when said pressure chamber is supplied with the pressurized fluid; and
a retainer ring provided at an outer peripheral portion of said top ring body and configured to be movable independently of said top ring body and to press said polishing surface;
wherein a fulcrum for receiving a lateral force applied from the substrate to said retainer ring during polishing of the substrate is located above a central portion of the substrate.
2. The apparatus according to claim 1 , wherein said retainer ring is tiltable about said fulcrum.
3. The apparatus according to claim 1 , wherein said retainer ring is vertically movably supported on an axis passing through said fulcrum.
4. The apparatus according to claim 1 , wherein said top ring body has at least one elastic membrane configured to form a plurality of pressure chambers for being supplied with a pressurized fluid; and
wherein said fulcrum is located above said pressure chamber located at the central portion of the substrate.
5. The apparatus according to claim 1 , wherein said fulcrum is located at a rotation center of a support mechanism for supporting said retainer ring by said top ring body.
6. An apparatus for polishing a substrate, comprising:
a polishing table having a polishing surface;
a top ring body having a pressure chamber for being supplied with a pressurized fluid and configured to press the substrate against said polishing surface under a fluid pressure when said pressure chamber is supplied with the pressurized fluid; and
a retainer ring provided at an outer peripheral portion of said top ring body and configured to be movable independently of said top ring body and to press said polishing surface;
wherein a support mechanism for supporting said retainer ring tiltably to allow said retainer ring to follow movement of said polishing surface is located above a central portion of the substrate.
7. The apparatus according to claim 6 , wherein said support mechanism supports said retainer ring vertically movably.
8. The apparatus according to claim 6 , wherein said retainer ring is movable independently of said top ring body by said support mechanism.
9. The apparatus according to claim 6 , wherein sliding contact surfaces of said support mechanism is composed of a low friction material.
10. The apparatus according to claim 6 , wherein said retainer ring comprises a ring member configured to hold an peripheral edge of the substrate, a holding portion disposed at a central portion of said top ring body and configured to hold said ring member, and a connecting portion for connecting said ring member and said holding portion; and
wherein said holding portion is supported by said support mechanism.
11. The apparatus according to claim 6 , wherein said top ring body has at least one elastic membrane configured to form a plurality of pressure chambers for being supplied with a pressurized fluid; and
wherein said support mechanism is located above said pressure chamber located at the central portion of the substrate.
12. The apparatus according to claim 6 , wherein said support mechanism comprises a spherical bearing mechanism for supporting said retainer ring rotatably by a spherical surface.
13. The apparatus according to claim 6 , wherein said support mechanism comprises a gyro mechanism for supporting said retainer ring rotatably about two orthogonal axes.
14. The apparatus according to claim 6 , wherein a metal ring is mounted on said retainer ring.
15. The apparatus according to claim 6 , further comprising a nozzle configured to supply a fluid for cooling said retainer ring.
16. The apparatus according to claim 6 , further comprising a rotary drive unit provided in said top ring body and configured to transmit a rotative force from said top ring body to said retainer ring.