Polishing apparatus and polishing method
A polishing apparatus capable of performing multi-stage polishing of a substrate, such as wafer, is disclosed. The polishing apparatus includes: a plurality of polishing tables each for supporting a polishing pad; a plurality of polishing heads each configured to press a substrate against the polishing pad; and a transporting device configured to transport the substrate to at least two of the plurality of polishing heads. The plurality of polishing heads have different structures.
1. A polishing method comprising:
providing a first polishing head having a plurality of pressure chambers;
holding a substrate by the first polishing head;
performing first profile control polishing of the substrate by pressing the substrate against a first polishing pad by the first polishing head;
providing a second polishing head having a plurality of pressure chambers whose arrangement is different from an arrangement of the pressure chambers of the first polishing head;
holding the substrate, which has been polished with use of the first polishing head, by the second polishing head; and
performing second profile control polishing of the substrate by pressing the substrate against a second polishing pad by the second polishing head.
2. The polishing method according to claim 1 , wherein the pressure chambers of the second polishing head are arranged at positions corresponding to positions of boundaries between the pressure chambers of the first polishing head.
3. The polishing method according to claim 1 , further comprising:
providing a rigid-body polishing head having a substrate holding material;
holding the substrate by the rigid-body polishing head;
performing rough polishing of the substrate by pressing the substrate against a polishing pad by the rigid-body polishing head;
providing a single-chamber polishing head having a single pressure chamber;
holding the substrate by the single-chamber polishing head;
performing final polishing of the substrate by pressing the substrate against a polishing pad by the single-chamber polishing head,
wherein the rough polishing, the first profile control polishing, the second profile control polishing, and the final polishing of the substrate are performed in this order.
4. The method according to claim 1 , comprising:
wherein pressing the substrate against the first polishing pad comprises receiving a pressure of a fluid within at least one of a plurality of pressure chambers of the first polishing head; and
wherein pressing the substrate against the second polishing pad to polish by the second polishing head comprises receiving a pressure of a fluid within at least one of the plurality of pressure chambers of the second polishing head,
wherein the plurality of the pressure chambers of the first polishing head comprises a first elastic membrane and the plurality of the pressure chambers of the second polishing head comprises a second elastic membrane having a hardness different from a hardness of the first elastic membrane.
5. The method according to claim 4 , wherein the second elastic membrane comprises a circumferential wall whose shape is different from a shape of a circumferential wall of the first elastic membrane.
6. The method according to claim 4 , wherein the second elastic membrane comprises a contact portion which is to be brought into contact with the substrate, the contact portion having a thickness different from that of a contact portion, which is to be brought into contact with the substrate, of the first elastic membrane.
7. The method according to claim 4 , wherein the second elastic membrane comprises a substrate pressing surface whose area is different from an area of a substrate pressing surface of the first elastic membrane.
8. The method according to claim 4 , wherein the second elastic membrane has a contact portion which is to be brought into contact with the substrate, the contact portion having an edge whose shape is different from a shape of an edge of a contact portion, which is to be brought into contact with the substrate, of the first elastic membrane.
9. The method according to claim 4 , further comprising:
surrounding the substrate with a first retainer ring of the first polishing head; and
pressing the first retainer ring of the first polishing head against the first polishing pad.
10. The method according to claim 9 , further comprising:
surrounding the substrate with a second retainer ring of the second polishing head, the second retainer ring having a structure different from that of the first retainer ring; and
pressing the second retainer ring of the second polishing head against the second polishing pad.