Elastic membrane
An elastic member for use in a substrate holding apparatus includes an elastic member and a first reinforcing member. The first reinforcing member has a higher rigidity than the elastic membrane and reinforces substantially an entire area of the contact portion of the elastic membrane. The contact portion of the elastic member has a contact portion for contact with the substrate. The first peripheral wall portion of the elastic membrane is coupled to a peripheral end of the contact portion and extends upwardly. The second peripheral wall portion of the elastic member defines a first chamber on an outer side thereof and a second chamber on an inner side thereof. The first reinforcing member is embedded in substantially the entire area of the contact portion of the elastic membrane.
1. An elastic member for use in a substrate holding apparatus for holding a substrate with a retainer ring located around a periphery of the substrate, said elastic member comprising:
an elastic membrane having a contact portion, a first peripheral wall portion, and a second peripheral wall portion; and
a first reinforcing member having a higher rigidity than the elastic membrane and reinforcing substantially an entire area of the contact portion of the elastic membrane,
wherein the contact portion of the elastic member has a contact portion for contact with the substrate,
wherein the first peripheral wall portion of the elastic membrane is coupled to a peripheral end of the contact portion and extends upwardly,
wherein the second peripheral wall portion of the elastic member is located on an inside of the first peripheral wall portion, is coupled to the contact portion and extends upwardly,
wherein the second peripheral wall portion of the elastic member defines a first chamber on an outer side thereof and a second chamber on an inner side thereof, and
wherein the first reinforcing member is embedded in substantially the entire area of the contact portion of the elastic membrane.
2. The elastic member of claim 1 , wherein the contact portion has a circular shape, and the first reinforcing member is comprised of thread-like members arranged in a radial pattern in substantially the entire area of the contact portion.
3. The elastic member of claim 1 , wherein the contact portion has a circular shape, and the first reinforcing member is comprised of annular thread-like members arranged in a concentric pattern in substantially the entire area of the contact portion.
4. The elastic member of claim 1 , wherein the contact portion has a circular shape, and the first reinforcing member is comprised of a thread-like member arranged in a spiral pattern in substantially the entire area of the contact portion.
5. The elastic member of claim 1 , wherein the first reinforcing member is comprised of thread-like members arranged in a grid-like pattern in substantially the entire area of the contact portion.
6. The elastic member of claim 1 , wherein the first reinforcing member is comprised of a non-woven fabric or a woven fabric disposed in substantially the entire area of the contact portion.
7. The elastic member of claim 1 , wherein the first reinforcing member is comprised of a resin plate disposed in substantially the entire area of the contact portion.
8. The elastic member of claim 1 , wherein the contact portion has suction holes, and the first reinforcing member is disposed in a region other than the suction holes and their vicinities.
9. The elastic member of claim 1 , wherein at least one of the first peripheral wall portion and the second peripheral wall portion is reinforced with a second reinforcing member having a higher rigidity than the elastic membrane.
10. The elastic member of claim 9 , wherein the second reinforcing member is comprised of annular thread-like members arranged at predetermined intervals in the height direction.
11. The elastic member of claim 9 , wherein the second reinforcing member is comprised of a coiled thread-like member.
12. The elastic member of claim 9 , wherein the second reinforcing member is comprised of a resin plate, a non-woven fabric or a woven fabric.
13. The elastic member of claim 1 , wherein a low-friction member is attached to an outer surface of the first peripheral wall portion.
14. The elastic member of claim 13 , wherein the low-friction member is a coating film.
15. The elastic member of claim 14 , wherein the coating film is an impregnated film.
16. The elastic member of claim 14 , wherein the coating film is a fluoropolymer film.
17. An elastic member for use in a substrate holding apparatus for holding a substrate with a retainer ring located around a periphery of the substrate, said elastic member comprising:
an elastic membrane having a contact portion, a first peripheral wall portion, and a second peripheral wall portion; and
a first reinforcing member having a higher rigidity than the elastic membrane and reinforcing substantially an entire area of the contact portion of the elastic membrane,
a second reinforcing member having a higher rigidity than the elastic membrane,
wherein the contact portion of the elastic member has a contact portion for contact with the substrate,
wherein the first peripheral wall portion of the elastic membrane is coupled to a peripheral end of the contact portion and extends upwardly,
wherein the second peripheral wall portion of the elastic member is located on an inside of the first peripheral wall portion, is coupled to the contact portion and extends upwardly,
wherein the second peripheral wall portion of the elastic member defines a first chamber on an outer side thereof and a second chamber on an inner side thereof, and
wherein the second reinforcing member reinforces at least one of the first peripheral wall portion and the second peripheral wall portion, excepting a junction of a vertical portion with the contact portion.
18. The elastic member of claim 17 , wherein the second reinforcing member is comprised of annular thread-like members arranged at predetermined intervals in the height direction.
19. The elastic member of claim 17 , wherein the second reinforcing member is comprised of a coiled thread-like member.
20. The elastic member of claim 17 , wherein the second reinforcing member is comprised of a resin plate, a non-woven fabric or a woven fabric.
21. The elastic member of claim 17 , wherein a low-friction member is attached to an outer surface of the first peripheral wall portion.
22. An elastic member for use in a substrate holding apparatus for holding a substrate with a retainer ring located around a periphery of the substrate, said elastic member comprising:
an elastic membrane having a contact portion, a first peripheral wall portion, and a second peripheral wall portion; and
a first reinforcing member having a higher rigidity than the elastic membrane and reinforcing substantially an entire area of the contact portion of the elastic membrane,
wherein the contact portion of the elastic member has a contact portion for contact with the substrate,
wherein the first peripheral wall portion of the elastic membrane is coupled to a peripheral end of the contact portion and extends upwardly,
wherein the second peripheral wall portion of the elastic member is located on an inside of the first peripheral wall portion, is coupled to the contact portion and extends upwardly,
wherein the second peripheral wall portion of the elastic member defines a first chamber on an outer side thereof and a second chamber on an inner side thereof, and
wherein a low-friction member is attached to an outer surface of the first peripheral wall portion.
23. The elastic member of claim 22 , wherein the low-friction member is a coating film.
24. The elastic member of claim 23 , wherein the coating film is an impregnated film.
25. The elastic member of claim 23 , wherein the coating film is a fluoropolymer film.