Claims
- 1. A chuck for supporting a workpiece comprising:
an upper support for mounting the workpiece, said upper support being characterized by a first temperature; a lower support for mounting the chuck to a base located under said lower support, said lower support comprising a temperature control device for affecting heat in the chuck, and said lower support being characterized by a second temperature; and non-constraining attachment means for holding the upper and lower supports together and holding the lower support and the base together while allowing substantially continuous relative movement between layers of the chuck caused by thermal expansion forces due to differential temperature effects between the layers of the chuck.
- 2. The chuck of claim 1 wherein the non-constraining attachment means comprises a vacuum.
- 3. The chuck of claim 1 wherein the non-constraining attachment means comprises at least one spring.
- 4. The chuck of claim 1 wherein the non-constraining attachment means comprises of at least one resilient washer.
- 5. The chuck of claim 1 wherein the non-constraining attachment means holds the workpiece on the upper support.
- 6. The chuck of claim 1 wherein the upper support comprises an electrically insulating material.
- 7. The chuck of claim 1 wherein the upper support comprises a ceramic material.
- 8. The chuck of claim 1 wherein the non-constraining attachment means comprises a patterened upper surface formed on the upper support for distributing vacuum to a bottom surface of the workpiece.
- 9. The chuck of claim 8 wherein the upper support further comprises a layer of metal formed over the patterned upper surface.
- 10. The chuck of claim 1 wherein the non-constraining attachment means comprises a patterned lower surface on the upper support for distributing vacuum on the patterned lower surface to hold the upper support to the lower support.
- 11. The chuck of claim 1 wherein said upper support includes a guard comprising a layer of metal.
- 12. The chuck of claim 1 wherein said lower support comprises at least one alignment pin protruding through a top surface of said lower support, said alignment pin being inserted into at least one corresponding alignment hole in a bottom surface of said upper support when said upper and lower supports are held together.
- 13. The chuck of claim 12 wherein the at least one alignment pin is press fit into said lower support.
- 14. The chuck of claim 12 wherein at least one alignment hole is elongated to allow relative radial movement between the lower support and upper support while preventing relative rotation between the upper support and lower support.
- 15. The chuck of claim 1 wherein said temperature control device comprises a heater for supplying heat to the workpiece.
- 16. The chuck of claim 15 wherein said temperature control device comprises a heat sink located between said heater and said upper support for controlling temperature of the workpiece.
- 17. The chuck of claim 1 wherein said temperature control device comprises a heat sink for controlling temperature of the workpiece.
- 18. The chuck of claim 17 wherein said heat sink comprises means for circulating a temperature-controlled fluid therethrough.
- 19. The chuck of claim 1 wherein said lower support comprises a ring attached to a lower surface of said lower support for providing a vacuum seal between said chuck and said base.
- 20. A method of supporting a workpiece with a chuck comprising:
providing an upper support for holding the workpiece, said upper support being characterized by a first temperature; providing a lower support for holding the chuck to a base located below said lower support, said lower support being characterized by a second temperature; providing a temperature control device in said lower support for affecting heat in the chuck; and holding the upper support and the lower support together in a non-constraining fashion and holding the lower support and the base together in a non-constraining fashion such that layers of the chuck can move substantially continuously relative to each other due to thermal expansion forces caused by differential temperature effects between the layers of the chuck.
- 21. The method of claim 20 wherein holding the upper support and the lower support together in a non-constraining fashion comprises applying a vacuum to the chuck.
- 22. The method of claim 20 wherein holding the upper support and the lower support together in a non-constraining fashion comprises applying at least one spring to the chuck.
- 23. The method of claim 20 wherein holding the upper support and the lower support together in a non-constraining fashion comprises applying at least one resilient washer to the chuck.
- 24. The method of claim 20 wherein providing a temperature control device in said lower support comprises providing a heater in said lower support for heating said workpiece.
- 25. The method of claim 24 wherein providing a temperature control device in said lower support comprises providing a heat sink in said lower support between said heater and said upper support for controlling temperature of said workpiece.
- 26. The method of claim 20 wherein providing a temperature control device in said lower support comprises providing a heat sink in said lower support for controlling temperature of said workpiece.
- 27. The method of claim 26 further comprising circulating a temperature-controlled fluid through said heat sink.
RELATED APPLICATIONS
[0001] This application is a continuation of pending U.S. patent application Ser. No. 09/001,893, filed on Dec. 31, 1997, the contents of which are incorporated herein in their entirety by reference.
Continuations (1)
|
Number |
Date |
Country |
Parent |
09001893 |
Dec 1997 |
US |
Child |
09516000 |
Feb 2000 |
US |