Method for modulating shapes of substrates

• US 6,980,282 B2
• Filed: 12/11/2002
• Issued: 12/27/2005
• Est. Priority Date: 12/11/2002
• Status: Expired due to Term

• Current Assignee: Mii Newco, Inc.
• Original Assignee: Molecular Imprints, Inc. (Canon Inc.)
• Inventors: Sreenivasan, Sidlgata V., Willson, C. Grant, Watts, Michael P. C., Voisin, Ronald D., Schumaker, Norman E., Meissl, Mario J., Choi, Byung J.
• Primary Examiner(s): Kim, Peter B.
• Application Number:
  US10/316,963
• Publication Number:
  US 20040112861A1
• Time in Patent Office: 1,112 Days
• Field of Search: 355/72, 355/75, 355/77, 355/53, 355/73, 355/76, 216/52, 216/2, 216/44, 216/67, 216/72, 438/691, 438/700, 438/735, 438/638, 438/692, 438/690, 264/479, 264/402, 264/338, 264/85
• US Class Current: 355/72
• CPC Class Codes: G03F 7/0002 Lithographic processes using patterning methods other than those involving the exposure to radiation, e.g. by stamping
• CPC Class Codes: G03F 7/707 Chucks, e.g. chucking or un-chucking operations or structural details
• CPC Class Codes: G03F 7/70875 Temperature, e.g. temperature control of masks or workpieces via control of stage temperature

Abstract

The present invention is directed to a method for modulating shapes of a substrate, having first and second opposed surfaces. This is achieved by creating a pressure differential between differing regions of the first opposed surface to attenuate structural distortions in the second opposed surface that results from external forces bearing on the substrate.

Claims

1. A method for modulating shapes of a substrate, having first and second opposed surfaces, with said second opposed surface facing an imprinting layer, said method comprising:

creating a pressure differential between differing regions of said first opposed surface to obtain a desired shape of said second opposed surface by compensating for external pressures bearing thereon resulting from contact by said second opposed surface with said imprinting layer.

2. The method as recited in claim 1 wherein creating further includes subjecting a first subset of said differing regions to a pulling force and subjecting a second subset of said differing regions to a pushing force to establish a sub portion of said second opposed surface to have a desired predetermined shape.

3. The method as recited in claim 1 wherein creating further includes subjecting a first subset of said differing regions to a pulling force that is substantially greater than a pulling force associated with the remaining regions of said differing regions, with said first subset being contiguous and positioned proximate to a periphery of said substrate.

4. The method as recited in claim 1 further including applying compressive forces to said substrate to vary dimensions thereof that induce a bending action, with creating further including creating a pulling force to attenuate said bending action and maintain a desired predetermined shape of a portion of said second opposed surface.

5. The method as recited in claim 1 wherein creating further includes establishing a first of said differing regions to cincture a second of said differing regions, with said first region having a pulling force applied thereto and said second region having a pushing force present thereon.

6. The method as recited in claim 1 wherein creating said pressure differential occurs dynamically.

7. The method as recited in claim 1 further including contacting said imprinting layer with said second opposed surface, separating said second opposed surface from said imprinting layer and terminating said pressure differential after separating by creating a positing pressure directed against said first opposed surface.

8. The method as recited in claim 1 further including providing said second opposed surface with a mold having a pattern disposed thereon facing said imprinting layer and contacting said imprinting layer with said mold, wherein creating further includes providing a chuck body having first and second opposed sides with an edge surface extending therebetween, said first opposed side including first and second spaced-apart recesses defining first and second spaced-apart support regions, resting said substrate against said first and second spaced-apart support regions, covering said first and second spaced-apart recesses, with said first recess and a first portion of said substrate in superimposition therewith defining a first chamber and said second recess and a second portion of said substrate in superimposition therewith defining a second chamber, with said pressure differential being created by establishing differing pressure levels within said first and second chambers to retain said substrate on said chuck body, and further including establishing a positive pressure within said second chamber after contacting said imprinting layer with said mold to remove said substrate from said chuck body.

9. The method as recited in claim 8 further including separating said mold from said imprinting layer and evacuating said second chamber before separating said mold from said imprinting layer.

10. The method as recited in claim 1 wherein creating said pressure differential further includes having a differing pressure associated with each of said differing regions.

11. A method for modulating shapes of a substrate, having first and second opposed surfaces with a side surface extending therebetween, said method comprising:

creating a pressure differential between differing regions of said first opposed surface; and

attenuating structural distortions in said second opposed surface by loading said side surface causing said substrate to bow and varying said pressure differential to compensate for external forces bearing on said side surface and said second opposed surface.

12. The method as recited in claim 11 wherein attenuating further includes obtaining information concerning a magnitude of said external forces and adjusting said pressure differential in response to said information to modulate a shape of said second opposed surface to a desired predetermined shape.

13. The method as recited in claim 12 wherein creating further includes providing a chuck body having first and second opposed sides with an edge surface extending therebetween, said first opposed side including first and second spaced-apart recesses defining first and second spaced-apart support regions, resting said substrate against said first and second spaced-apart support regions, covering said first and second spaced-apart recesses, with said first recess and a first portion of said substrate in superimposition therewith defining a first chamber and said second recess and a second portion of said substrate in superimposition therewith defining a second chamber establishing, with said pressure differential being created by establishing differing pressure levels within said first and second chambers.

14. The method as recited in claim 12 further including disposing a wafer opposite said second opposed surface and moving, with said chuck body, said second opposed surface so that a portion thereof, in superimposition with said second chamber, contacts said wafer, resulting in a force being exerted on said portion in a direction toward said second opposed surface, with attenuating further including pressurizing said second chamber with sufficient positive fluid pressure to establish said portion to have a desired predetermined shape.

15. The method as recited in claim 12 further including disposing a wafer opposite said second opposed surface and moving, with said chuck body, said second opposed surface so that a portion thereof, in superimposition with said second chamber, contacts said wafer, resulting in an impact force being exerted on said portion in a direction toward said second opposed surface, and applying compressive forces to said side surface to vary dimensions of said substrate creating a bending force that bends said substrate in a predetermined direction, with attenuating further including determining a relative magnitude difference between said bending force and said impact force and pressurizing said second chamber appropriately to establish said portion to have a desired predetermined shape.

16. The method as recited in claim 11 further including providing said second opposed surface with a mold having a pattern disposed thereon facing an imprinting layer and contacting said imprinting layer with said mold, wherein creating said pressure differential further includes providing a chuck body having first and second opposed sides with an edge surface extending therebetween, said first opposed side including first and second spaced-apart recesses defining first and second spaced-apart support regions, resting said substrate against said first and second spaced-apart support regions, covering said first and second spaced-apart recesses, with said first recess and a first portion of said substrate in superimposition therewith defining a first chamber and said second recess and a second portion of said substrate in superimposition therewith defining a second chamber, with attenuating further including establishing a positive pressure within said second chamber after contacting said imprinting layer with said mold.

17. The method as recited in claim 16 further including disposing a wafer opposite said second opposed surface having said imprinting layer disposed thereon and creating relative movement between said second opposed surface and said wafer so that a portion of said second opposed surface, in superimposition with said second chamber, contacts said imprinting layer, and increasing a distance between said portion and said wafer after contact, with a rate at which said distance changes for differing sub-portions being different and defined by said pressure differential.

18. A method for modulating shapes of a substrate, having first and second opposed surfaces with a side surface extending therebetween, said substrate being spaced-apart from a wafer having an imprinting layer disposed thereon, said method comprising:

defining a plurality of pressure chambers in fluid communication with said first opposed surface by providing a chuck body having first and second opposed sides with an edge surface extending therebetween, said first opposed side including first and second spaced-apart recesses defining first and second spaced-apart support regions, resting said substrate against said first and second spaced-apart support regions, covering said first and second spaced-apart recesses, with said first recess and a first portion of said substrate in superimposition therewith defining a first chamber and said second recess and a second portion of said substrate in superimposition therewith defining a second chamber;

hydrostatically supporting said substrate against gravity by creating a pressure differential between said first and second chambers; and

attenuating structural distortions in said second opposed surface by loading said side surface causing said substrate to bow and varying said pressure of said second chamber to compensate for external forces bearing on said side surface and said second opposed surface.

19. The method as recited in claim 18 wherein attenuating further includes obtaining information concerning a magnitude of said external forces and adjusting said pressure differential in response to said information to modulate a shape of said second opposed surface to a desired predetermined shape.

20. The method as recited in claim 19 further including disposing said wafer opposite said second opposed surface and moving, with said chuck body, said second opposed surface so that a portion thereof, in superimposition with said second chamber, contacts said wafer, resulting in a contact force being exerted on said portion in a direction toward said second opposed surface, with attenuating further including pressurizing said second chamber with sufficient positive fluid pressure to establish said portion to have a desired predetermined shape.

21. The method as recited in claim 20 further including applying compressive forces to said side surface to vary dimensions of said substrate creating a bending force that bends said substrate in a predetermined direction, with attenuating further including determining a relative magnitude difference between said bending force and said contact force and pressurizing said second chamber appropriately to establish said portion to have said desired predetermined shape.

22. The method as recited in claim 21 further including creating a relative movement between said second opposed surface and said wafer so that said portion contacts said imprinting layer, and increasing a distance between said portion and said imprinting layer after contact, with a rate at which said distance changes for differing sub-portions being different and defined by said pressure differential.

23. A method for modulating shapes of a substrate, having first and second opposed surfaces and a side surface extending therebetween, with said second opposed surface having a pattern disposed thereon and facing an imprinting layer, said method comprising:

loading said side surface causing said substrate to bow;

creating a pressure differential between differing regions of said first opposed surface to attenuate distortions in said pattern while maintaining a desired predetermined shape of said second opposed surface.

24. A method for modulating shapes of a substrate, having first and second opposed surfaces with a side surface extending therebetween, said substrate being spaced-apart from a wafer having an imprinting layer disposed thereon, said method comprising:

hydrostatically supporting said substrate against gravity by creating a pressure differential between first and second regions of said first opposed surface; and

attenuating structural distortions in said second opposed surface by dynamically varying said pressure associated with said second region to compensate for varying external pressures bearing on said second opposed surfaces that results from contacting said imprinting layer with said substrate.