Formation of discontinuous films during an imprint lithography process

• US 6,932,934 B2
• Filed: 07/11/2002
• Issued: 08/23/2005
• Est. Priority Date: 07/11/2002
• Status: Expired due to Term

• Current Assignee: Mii Newco, Inc. (Canon Inc.)
• Original Assignee: Molecular Imprints, Inc. (Canon Inc.)
• Inventors: Watts, Michael P. C., Choi, Byung Jin, Meissl, Mario J., Sreenivasan, Sidlagata V.
• Primary Examiner(s): Tentoni, Leo B.
• Application Number:
  US10/194,411
• Publication Number:
  US 20040007799A1
• Time in Patent Office: 1,139 Days
• Field of Search: 264/40.1, 264/259, 264/293, 264/338, 264/494, 264/496, 216/11, 216/52
• US Class Current: 264/496
• CPC Class Codes: B29C 2035/0827 using UV radiation
• CPC Class Codes: B29C 2059/023 Microembossing
• CPC Class Codes: B29C 35/0888 using transparant moulds
• CPC Class Codes: B29C 59/022 characterised by the disposition or the configuration, e.g. dimensions, of the embossments or the shaping tools therefor
• CPC Class Codes: B29C 59/026 of layered or coated substantially flat surfaces
• CPC Class Codes: B81C 1/0046 using stamping, e.g. imprinting nanoimprinting for making etch masks G03F7/0002
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• 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: H01L 21/0271 comprising organic layers

Abstract

The present invention is directed to methods for patterning a substrate by imprint lithography. An imprint lithography method includes placing a curable liquid on a substrate. A template may be contacted with the curable liquid. Surface forces at the interface of the curable liquid and the template cause the curable liquid to gather in an area defined by a lower surface of the template. Alternately, the curable liquid may fill one or more relatively shallow recesses in the template and the area under the template lower surface. Activating light is applied to the curable liquid to form a patterned layer on the substrate.

Claims

1. A method of forming a pattern on a substrate, the method comprising:

obtaining a patterned template, the patterned template comprising a first surface and a plurality of recesses formed in the patterned template extending from the first surface toward an opposing second surface, where the plurality of recesses define a plurality of features in the first surface of the patterned template;

applying a predetermined amount of activating light curable liquid to a portion of the substrate;

positioning the patterned template and the substrate in a spaced relationship to each other so that a gap is created between the patterned template and the substrate, wherein the patterned template is positioned such that the applied activating light curable liquid substantially fills the gap between non-recessed portions of the patterned template and the substrate, and wherein the activating light curable liquid is substantially absent from regions of the substrate approximately below the plurality of recesses of the patterned template; and

applying an activating light to the activating light curable liquid, wherein the application of activating light substantially cures the activating light curable liquid, defining a cured liquid.

2. The method of claim 1, wherein the activating light curable liquid has a viscosity of less than about 30 centipoise measured at 25°

C.

3. The method of claim 1, wherein the activating light curable liquid has a viscosity of less than about 5 centipoise measured at 25°

C.

4. The method of claim 1, wherein at least a portion of the first surface of the patterned template comprises a surface treatment layer.

5. The method of claim 1, wherein the patterned template further comprises a surface treatment layer on at least a portion of the first surface, and wherein the surface treatment layer comprises a reaction product of an alkylsilane, a fluoroalkylsilane, or a fluoroalkyltrichlorosilane with water.

6. The method of claim 1, wherein the patterned template further comprises a surface treatment layer on at least a portion of the first surface, and wherein the surface treatment layer comprises a reaction product of tridecafluoro-1,1,2,2-tetrahydrooctyl trichlorosilane with water.

7. The method of claim 1, wherein the patterned template further comprises a surface treatment layer on at least a portion of the first surface, and wherein the surface treatment layer reduces a surface free energy of the first surface measured at 25°

C. to less than about 40 dynes/cm.

8. The method of claim 1, wherein the patterned template further comprises a first surface treatment layer on at least a portion of the first surface, and a second surface treatment layer on the plurality of recesses of the patterned template, wherein the first and second surface treatment layers have different wetting characteristics with respect to the activating light curable liquid.

9. The method of claim 1, wherein the patterned template further comprises a surface treatment layer on at least a portion of the first surface, and wherein the surface treatment layer comprises a monolayer.

10. The method of claim 1, wherein the patterned template is substantially transparent to the activating light.

11. The method of claim 1, wherein at least a portion of the patterned template comprises silicon, silicon dioxide, silicon germanium carbon, gallium nitride, silicon germanium, sapphire, gallium arsenide, epitaxial silicon, poly-silicon, gate oxide, quartz, indium tin oxide, an oxide of silicon or a combination thereof.

12. The method of claim 1, wherein applying the activating light curable liquid to a portion of the substrate comprises dispensing the activating light curable liquid with a fluid dispenser.

13. The method of claim 1, wherein applying the activating light curable liquid to a portion of the substrate comprises dispensing the activating light curable liquid with a fluid dispenser such that a predetermined pattern of the activating light curable liquid is produced on the portion of the substrate.

14. The method of claim 1, wherein applying the activating light curable liquid to a portion of the substrate comprises applying the activating light curable liquid to areas of the substrate corresponding to areas of the patterned template that are not recessed and not applying the activating light curable liquid to areas of the substrate corresponding to areas of the patterned template that are recessed.

15. The method of claim 1, wherein the activating light curable liquid comprises an ultraviolet light curable composition.

16. The method of claim 1, wherein positioning the patterned template and the substrate in a spaced relationship further comprises:

positioning the patterned template over the substrate; and

moving the patterned template toward the substrate until a desired spaced relationship is achieved, wherein the activating light curable liquid on the substrate substantially fills the gap between the non-recessed portions of the patterned template and the substrate as the patterned template is positioned over the substrate.

17. The method of claim 1, wherein positioning the patterned template and the substrate in the spaced relationship further comprises positioning the patterned template at a distance of less than about 500 nm from the substrate.

18. The method of claim 1, further comprising separating the patterned template from the cured liquid.

19. The method of claim 18, wherein separating the patterned template from the cured liquid further comprises:

moving the patterned template to a substantially non-parallel orientation with respect to the substrate; and

moving the patterned template away from the substrate.

20. The method of claim 18, further comprising applying a separating light to the cured liquid before separating the patterned template from the cured liquid, wherein the separating light alters a chemical composition of a portion of the cured liquid such that an adhesion of the patterned template to the cured liquid is reduced.

21. The method of claim 18, further comprising applying a separating light to the cured liquid before separating the patterned template from the cured liquid, wherein the separating light alters a chemical composition of a portion of the cured liquid such that a gas is released by the cured liquid near an interface of the patterned template and the cured liquid.

22. The method of claim 18, wherein the cured liquid comprises at least some features less than about 250 nm in size after the patterned template is separated from the cured liquid.

23. The method of claim 1, further comprising determining an alignment between the patterned template and the substrate prior to applying the activating light.

24. The method of claim 1, further comprising adjusting an overlay placement of the patterned template and the substrate;

wherein the patterned template comprises a template alignment mark and the substrate comprises a substrate alignment mark, wherein adjusting the overlay placement comprises a relative motion between the substrate and the patterned template such that the template alignment mark is substantially aligned with the substrate alignment mark.

25. The method of claim 1, further comprising sensing a distance between the patterned template and the substrate, and altering the distance between the patterned template and the substrate, prior to applying the activating light to the activating light curable liquid.

26. The method of claim 1, further comprising sensing a force applied to position the patterned template and the substrate in a spaced relationship, and altering the force applied to the patterned template prior to applying the activating light to the activating light curable liquid.

27. The method of claim 1, further comprising:

forming a transfer layer on the substrate prior to applying the activating light curable liquid to the substrate; and

etching the transfer layer after separating the patterned template from the substrate, wherein etching the transfer layer imparts the pattern to the transfer layer.

28. The method of claim 1, wherein the substrate comprises a magnetic data storage medium.

29. The method of claim 1, wherein the substrate comprises silicon, silicon dioxide, gallium arsenide, silicon germanium, silicon germanium carbide or indium phosphide.

30. The method of claim 1, wherein the substrate comprises at least one layer on a surface of the substrate.

31. A method of forming a pattern on a substrate, the method comprising:

obtaining a patterned template, the patterned template comprising a first surface, a plurality of first recesses formed in the patterned template extending from the first surface toward an opposing second surface of the patterned template, and a plurality of second recesses extending from the first surface toward the second surface of the patterned template, wherein the first and the second recesses define a plurality of features on the first surface of the patterned template, and wherein a depth of any of the first recesses is substantially less than a depth of any of the second recesses;

applying a predetermined amount of activating light curable liquid to a portion of the substrate;

positioning the patterned template and the substrate in a spaced relation to each other so that a gap is created between the patterned template and the substrate, wherein a distance between the non-recessed surface of the patterned template and the substrate is such that the activating light curable liquid substantially contacts the non-recessed portions of the first surface of the patterned template and surfaces of the plurality of first recesses, and wherein the activating light curable liquid is substantially absent from regions of the substrate approximately below the plurality of second recesses of the patterned template; and

applying an activating light to the activating light curable liquid, wherein the application of activating light substantially cures the activating light curable liquid, defining a cured liquid.

32. The method of claim 31, wherein the activating light curable liquid has a viscosity of less than about 30 centipoise measured at 25°

C.

33. The method of claim 31, wherein at least a portion of the first surface of the patterned template comprises a surface treatment layer.

34. The method of claim 31, further comprising applying a separating light to the cured liquid, wherein the separating light alters a chemical composition of a portion of the cured liquid such that an adhesion of the patterned template to the cured liquid is reduced, and separating the patterned template from the cured liquid.

35. The method of claim 31, further comprising applying a separating light to the cured liquid, wherein the separating light alters a chemical composition of a portion of the cured liquid such that a gas is released by the cured liquid near an interface of the patterned template and the cured liquid, and separating the patterned template from the cured liquid.

36. The method of claim 31, further comprising sensing a force applied to position the patterned template and the substrate in a spaced relationship, and altering the force applied to the patterned template prior to applying the activating light to the activating light curable liquid.

37. The method of claim 31, wherein the distance between the non-recessed surface of the patterned template and the substrate is between a minimum film thickness and a maximum film thickness.

38. A method of forming a pattern on a substrate, the method comprising:

applying an activating light curable liquid to a portion of the substrate;

positioning a patterned template and the substrate in a spaced relation to each other such that a gap is created between the patterned template and the substrate, wherein the patterned template comprises a plurality of recesses extending from a first surface of the patterned template toward an opposing second surface of the patterned template, wherein the plurality of recesses define a plurality of features in the first surface, and wherein at least a portion of non-recessed portions of the patterned template contact the activating light curable liquid;

controlling a distance between the patterned template and the substrate such that surface forces at a liquid-template interface and a liquid-substrate interface shape the activating light curable liquid into a desired pattern substantially the same as the non-recessed portions of the patterned template; and

applying an activating light to the activating light curable liquid, wherein the application of the activating light substantially cures the activating light curable liquid, defining a cured liquid.

39. The method of claim 38, wherein the activating light curable liquid has a viscosity of less than about 30 centipoise measured at 25°

C.

40. The method of claim 38, wherein at least a portion of the first surface of the patterned template comprises a surface treatment layer.

41. The method of claim 38, further comprising applying a separating light to the cured liquid, wherein the separating light alters a chemical composition of a portion of the cured liquid such that an adhesion of the patterned template to the cured liquid is reduced, and separating the patterned template from the cured liquid.

42. The method of claim 38, further comprising applying a separating light to the cured liquid, wherein the separating light alters a chemical composition of a portion of the cured liquid such that a gas is released by the cured liquid near the liquid-template interface, and separating the patterned template from the cured liquid.

43. The method of claim 38, further comprising sensing a force applied to position the patterned template and the substrate in a spaced relationship, and altering the force applied to the patterned template prior to applying the activating light to the activating light curable liquid.

44. The method of claim 38, wherein the distance between the non-recessed surface of the patterned template and the substrate is between a minimum film thickness and a maximum film thickness.

45. A method of forming a pattern on a substrate, the method comprising:

applying an activating light curable liquid to a portion of the substrate;

positioning a patterned template and the substrate in a spaced relation to each other such that a gap is created between the patterned template and the substrate, wherein the patterned template comprises a plurality of recesses extending from a first surface of the patterned template toward an opposing second surface of the patterned template, wherein the plurality of recesses define a plurality of features in the first surface, and wherein at least a portion of the non-recessed portions of the patterned template contact the activating light curable liquid;

controlling a force applied to the patterned template such that surface forces at a liquid-template interface and a liquid-substrate interface shape the activating light curable liquid into a desired pattern substantially the same as the non-recessed portions of the patterned template; and

applying an activating light to the activating light curable liquid, wherein the application of activating light substantially cures the activating light curable liquid, defining a cured liquid.

46. The method of claim 45, wherein the activating light curable liquid has a viscosity of less than about 30 centipoise measured at 25°

C.

47. The method of claim 45, wherein at least a portion of the first surface of the patterned template comprises a surface treatment layer.

48. The method of claim 45, further comprising applying a separating light to the cured liquid, wherein the separating light alters a chemical composition of a portion of the cured liquid such that an adhesion of the patterned template to the cured liquid is reduced, and separating the patterned template from the cured liquid.

49. The method of claim 45, further comprising applying a separating light to the cured liquid, wherein the separating light alters a chemical composition of a portion of the cured liquid such that a gas is released by the cured liquid near the liquid-template interface, and separating the patterned template from the cured liquid.

50. The method of claim 45, further comprising sensing the force applied to position the patterned template and the substrate in a spaced relationship, and altering the force applied to the patterned template prior to applying the activating light to the activating light curable liquid.

51. A method of forming a pattern on a substrate, the method comprising:

obtaining a patterned template, the patterned template comprising a first surface and a plurality of recesses formed in the patterned template extending from the first surface toward an opposing second surface, wherein the plurality of recesses define a plurality of features in the first surface of the patterned template;

applying an activating light curable liquid to a portion of the substrate, wherein the activating light curable liquid has a viscosity of less than about 30 centipoise measured at 25°

C.;

positioning the patterned template and the substrate in a spaced relationship to each other so that a gap is created between the patterned template and the substrate, wherein the patterned template is positioned such that the applied activating light curable liquid substantially fills the gap between non-recessed portions of the patterned template and the substrate, and wherein the activating light curable liquid is substantially absent from regions of the substrate approximately below the plurality of recesses of the patterned template; and

applying an activating light to the activating light curable liquid, wherein the application of the activating light substantially cures the activating light curable liquid, defining a cured liquid.

52. The method of claim 51, wherein at least a portion of the first surface of the patterned template comprises a surface treatment layer.

53. The method of claim 51, further comprising applying a separating light to the cured liquid, wherein the separating light alters a chemical composition of a portion of the cured liquid such that an adhesion of the patterned template to the cured liquid is reduced, and separating the patterned template from the cured liquid.

54. The method of claim 51, further comprising applying a separating light to the cured liquid, wherein the separating light alters a chemical composition of a portion of the cured liquid such that a gas is released by the cured liquid near an interface of the patterned template and the cured liquid, and separating the patterned template from the cured liquid.

55. The method of claim 51, further comprising sensing a force applied to position the patterned template and the substrate in a spaced relationship, and altering the force applied to the patterned template prior to applying the activating light to the activating light curable liquid.