초록 ▼

Edge grippers are disposed around an outer edge of a chuck. Each of the edge grippers includes a finger configured to pivot around a point; a contact pad configured to contact the wafer; and a flexure disposed between the contact pad and the finger. The flexure is configured to flex toward and away

Edge grippers are disposed around an outer edge of a chuck. Each of the edge grippers includes a finger configured to pivot around a point; a contact pad configured to contact the wafer; and a flexure disposed between the contact pad and the finger. The flexure is configured to flex toward and away from the chuck. The chuck can use a matrix of vacuum and pressure nozzles designed to keep a wafer floating above the chuck. The edge grippers can hold the wafer at the edge while minimizing deformation of the wafer or without affecting z-jitter of the wafer.

대표청구항 ▼

1. An apparatus comprising: a chuck having a surface with a plurality of gas flow openings configured to provide a flow of gas, wherein the surface of the chuck is in a plane perpendicular to a vertical direction;a plurality of edge grippers disposed around an outer edge of the chuck, wherein one of

1. An apparatus comprising: a chuck having a surface with a plurality of gas flow openings configured to provide a flow of gas, wherein the surface of the chuck is in a plane perpendicular to a vertical direction;a plurality of edge grippers disposed around an outer edge of the chuck, wherein one of the edge grippers is configured to push against a remainder of the edge grippers, and wherein each of the edge grippers includes: a finger configured to pivot around a point;a contact pad configured to contact a wafer; anda flexure disposed between the contact pad and the finger, wherein the flexure is configured to flex toward and away from the chuck in the vertical direction; andan actuator connected to at least one of the edge grippers. 2. The apparatus of claim 1, wherein the edge grippers are configured to prevent the wafer from rotating in a direction perpendicular to the vertical direction. 3. The apparatus of claim 2, wherein the chuck is configured to spin the wafer up to 6,000 rpm. 4. The apparatus of claim 1, wherein the actuator is a magnetic drive configured to cause the finger to pivot around the point. 5. The apparatus of claim 1, wherein the contact pad is fabricated of a perfluoroelastomer or polyether ether ketone. 6. The apparatus of claim 1, wherein three of the edge grippers are disposed around the outer edge of the chuck. 7. The apparatus of claim 1, wherein the contact pad has a planar surface disposed on the wafer. 8. The apparatus of claim 1, wherein the plurality of edge grippers are disposed uniformly around the outer edge of the chuck. 9. The apparatus of claim 1, wherein the finger is fabricated of aluminum, plastic, or steel. 10. The apparatus of claim 1, wherein the flexure is fabricated of aluminum, steel, or a plastic. 11. The apparatus of claim 1, wherein each of the edge grippers further includes a spring, and wherein the spring is configured to provide a force to the contact pad parallel to the surface of the chuck. 12. The apparatus of claim 1, wherein the chuck defines a plurality of recesses, and wherein one of the edge grippers is disposed in each of the recesses. 13. A method comprising: floating a wafer above a chuck on an air-vacuum film between a surface of the chuck and the wafer, wherein the surface of the chuck is in a plane perpendicular to a vertical direction;contacting the wafer with a plurality of edge grippers, wherein each of the edge grippers includes: a finger configured to pivot around a point;a contact pad configured to contact a wafer; anda flexure disposed between the contact pad and the finger, wherein the flexure is configured to flex toward and away from the chuck in the vertical direction; andactuating only one of the edge grippers to push the wafer against a remainder of the edge grippers. 14. The method of claim 13, further comprising spinning the wafer at a rate up to 6,000 rpm using the chuck.