Step and repeat imprint lithography processes

• US 7,077,992 B2
• Filed: 07/11/2002
• Issued: 07/18/2006
• Est. Priority Date: 07/11/2002
• Status: Active Grant

• Current Assignee: Mii Newco, Inc.
• Original Assignee: Molecular Imprints, Inc. (Canon Inc.)
• Inventors: Sreenivasan, Sidlgata V., Watts, Michael P. C., Voisin, Ronald D., Schumaker, Norman E., Meissl, Mario J., Choi, Byung J.
• Primary Examiner(s): Tentoni, Leo B.
• Application Number:
  US10/194,991
• Publication Number:
  US 20040124566A1
• Time in Patent Office: 1,468 Days
• Field of Search: 264/40.1, 264/259, 264/293, 264/338, 264/494, 264/496
• US Class Current: 264/496
• 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

Abstract

The present invention is directed to methods for patterning a substrate by imprint lithography. Imprint lithography is a process in which a liquid is dispensed onto a substrate. A template is brought into contact with the liquid and the liquid is cured. The cured liquid includes an imprint of any patterns formed in the template. In one embodiment, the imprint process is designed to imprint only a portion of the substrate. The remainder of the substrate is imprinted by moving the template to a different portion of the template and repeating the imprint lithography process.

Claims

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

applying a first predetermined volume of an activating light curable liquid to a first portion of the substrate in a first predetermined pattern;

positioning a patterned template and the substrate in a first spaced relation to each other so that a first gap is created between the patterned template and the substrate, wherein the first gap is established such that the activating light curable liquid contacts substantially an entirety of a first patterning area of the patterned template but does not substantially extend past a perimeter of the first patterning area;

applying an activating light to the activating light curable liquid, wherein the application of the activating light substantially cures the activating light curable liquid, forming a first patterned area of a cured liquid;

separating the patterned template from the cured liquid;

applying a second predetermined volume of the activating light curable liquid to a second portion of the substrate in a second predetermined pattern;

positioning the patterned template and the substrate in a second spaced relation to each other so that a second gap is created between the patterned template and the substrate, wherein the second gap is established such that the activating light curable liquid contacts substantially an entirety of a second patterning area of the patterned template but does not substantially extend past the perimeter of the second patterning area; and

applying the activating light to the activating light curable liquid on the second portion of the substrate, wherein the application of the activating light substantially cures the activating light curable liquid on the second portion of the substrate, forming a second patterned area.

2. The method of claim 1, wherein the patterned template comprises a first surface and a plurality of recesses formed in one or more patterning areas of the patterned template extending from the first surface toward a second surface of the patterned template, wherein the plurality of recesses define a plurality of features in the first surface of the patterned template.

3. The method of claim 2, wherein the patterned template comprises a border formed about a perimeter of one or more of the patterning areas, wherein a depth of the border is greater than a depth of the plurality of recesses.

4. The method of claim 1, wherein the patterned template comprises two or more patterning areas, each of the two or more patterning areas comprising a plurality of recesses, and wherein the two or more patterning areas are separated from each other by a channel, and wherein a depth of the channel is greater than a depth of the plurality of recesses in the two or more patterning areas.

5. The method of claim 1, wherein the patterned template comprises at least one template alignment mark, and wherein the substrate comprises at least one substrate alignment mark;

and wherein the method further comprises determining an alignment of the at least one template alignment mark with respect to the at least one substrate alignment mark, and altering a position of the patterned template with respect to the substrate such that the at least one substrate alignment mark and the at least one template alignment mark are substantially aligned before applying the activating light to the activating light curable liquid.

6. The method of claim 5, wherein the substrate is disposed on a motion stage, and wherein determining the alignment between the at least one template alignment mark and the at least one substrate alignment mark comprises determining a motion of the motion stage required to align the at least one template alignment mark with respect to the at least one substrate alignment mark.

7. The method of claim 1, further comprising adjusting a position of the patterned template such that a patterning surface of the patterned template is substantially parallel with a reference plane;

and adjusting a position of the substrate so that a surface of the substrate to be patterned is substantially parallel with the reference plane.

8. The method of claim 1, wherein separating the patterned template from the cured liquid comprises moving the patterned template and the substrate into a substantially non-parallel orientation with respect to one another;

and moving the patterned template and the substrate apart from one another.

9. The method of claim 1, further comprising applying a separating light 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.

10. The method of claim 1, further comprising applying a separating light 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.

11. The method of claim 1, further comprising providing an enclosure around at least the patterned template and the substrate and inhibiting temperature variations greater than about 1.0°

C. within at least a portion of the enclosure.

12. The method of claim 1, wherein the applied activating light curable liquid does not cover an entirety of the first portion of the substrate prior to positioning the patterned template and the substrate in a spaced relationship.

13. The method of claim 2, wherein each of the first and the second predetermined volumes is less than or equal to a volume defined by the non-recessed portions of the patterned template, a portion of the substrate to be patterned, and a maximum fluid film thickness at which surface forces of a liquid-template interface and a liquid-substrate interface are sufficient to inhibit spreading of the activating light curable liquid beyond a perimeter of the patterned template.

14. The method of claim 2, wherein each of the first and second predetermined volumes is less than or equal to a volume defined by a volume of the activating light curable liquid required to substantially fill the plurality of recesses of the patterned template, a portion of the substrate to be patterned, and a maximum fluid film thickness at which surface forces of a liquid-template interface and a liquid-substrate interface are sufficient to inhibit spreading of the activating light curable liquid beyond a perimeter of the patterned template.

15. The method of claim 1, further comprising applying a transfer layer to the substrate before applying the first predetermined volume of the activating light curable liquid to the first portion of the substrate, wherein the transfer layer etches at a different rate than an etch rate of the cured liquid under the same etching conditions.

16. The method of claim 1, wherein positioning the patterned template and the substrate in a spaced relation to each other comprises coupling the patterned template to an imprint head and coupling the substrate to a motion stage, wherein the imprint head is located above the motion stage.

17. The method of claim 1, wherein positioning the patterned template and the substrate in a spaced relation to each other comprises pushing the patterned template into the activating light curable liquid and controlling a position of the substrate so that a substantially parallel orientation of the patterned template and the substrate is maintained as the patterned template pushes into the activating light curable liquid.

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

C.

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

C.

20. The method of claim 2, wherein at least a portion of the first surface of the patterned template comprises a surface treatment layer.

21. The method of claim 2, 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.

22. The method of claim 2, 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.

23. The method of claim 2, wherein the 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.

24. The method of claim 2, wherein the patterned template 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 template, wherein the first and second surface treatment layers have different wetting characteristics with respect to the activating light curable liquid.

25. The method of claim 2, wherein the 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.

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

27. 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.

28. The method of claim 1, wherein applying the activating light curable liquid to the first and the second portions of the substrate comprises dispensing the activating light curable liquid with a fluid dispenser.

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

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

31. The method of claim 1, wherein positioning the patterned template and the substrate in the first and the second spaced relations comprises positioning the patterned template at a distance of less than about 500 nm from the substrate.

32. The method of claim 1, 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.

33. The method of claim 1, further comprising determining a distance between the patterned template and the substrate by sensing a resistive force between the patterned template and the activating light curable liquid.

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

35. A method of planarizing a substrate, the method comprising:

obtaining a template, the template comprising at least one planarizing area, wherein the at least one planarizing area comprises a substantially planar surface;

applying a first predetermined volume of an activating light curable liquid to a first portion of the substrate in a first predetermined pattern;

positioning the template and the substrate in a first spaced relation to each other so that a first gap is created between the template and the substrate, wherein the first gap is established such that the activating light curable liquid contacts substantially an entirety of a first planarizing area of the template but does not substantially extend past a perimeter of the first planarizing area;

applying an activating light to the activating light curable liquid, wherein the application of the activating light substantially cures the activating light curable liquid, forming a first planar area of a cured liquid on the substrate;

separating the template from the cured liquid;

applying a second predetermined volume of the activating light curable liquid to a second portion of the substrate in a second predetermined pattern;

positioning the template and the substrate in a second spaced relation to each other so that a second gap is created between the template and the substrate, wherein the second gap is established such that the activating light curable liquid contacts substantially an entirety of a second planarizing area of the template but does not substantially extend past a perimeter of the second planarizing area; and

applying the activating light to the activating light curable liquid on the second portion of the substrate, wherein the application of the activating light substantially cures the activating light curable liquid on the second portion of the substrate forming a second planar area on the substrate.

36. The method of claim 35, further comprising applying a separating light before separating the 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 template to the cured liquid is reduced.

37. The method of claim 35, further comprising applying a separating light before separating the 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 template and the cured liquid.

38. The method of claim 35, further comprising providing an enclosure around at least the template and the substrate and inhibiting temperature variations greater than about 1.0°

C. within at least a portion of the enclosure.

39. The method of claim 35, wherein the activating light curable liquid has a viscosity of less than about 30 centipoise measured at 25°

C.

40. The method of claim 35, wherein at least a portion of a surface of the patterned template comprises a surface treatment layer.

41. The method of claim 35, further comprising determining a distance between the template and the substrate by sensing a resistive force between the template and the activating light curable liquid.

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

obtaining a template, the template comprising at least one patterning area and at least one border surrounding the at least one patterning area, wherein the at least one patterning area comprises a pattern desired to be transferred to the substrate;

applying a predetermined volume of an activating light curable liquid to the template in a predetermined pattern, wherein the predetermined pattern does not cover an entirety of the at least one patterning area of the template;

positioning the template and the substrate in a spaced relation to each other so that a first area of the substrate to be patterned is over the template, and so that a gap is created between the template and the substrate, wherein the gap is established such that the activating light curable liquid contacts substantially an entirety of the at least one patterning area of the template but does not substantially extend into the at least one border;

applying an activating light to the activating light curable liquid, wherein the application of activating light substantially cures the activating light curable liquid, forming a first patterned area of a cured liquid; and

separating the template from the cured liquid.

43. The method of claim 42, further comprising:

applying an additional predetermined volume of the activating light curable liquid to the template in an additional predetermined pattern, wherein the additional predetermined pattern does not cover an entirety of the at least one patterning area of the template;

positioning the template and the substrate in a spaced relation to each other so that a second area of the substrate to be patterned is over the template, and so that an additional gap is created between the template and the substrate, wherein the additional gap is established such that the activating light curable liquid contacts substantially an entirety of the at least one patterning area of the template but does not substantially extend into the at least one border; and

applying the activating light to the activating light curable liquid, wherein the application of the activating light substantially cures the activating light curable liquid, forming a second patterned area.

44. The method of claim 42, further comprising applying a separating light before separating the 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 template to the cured liquid is reduced.

45. The method of claim 42, further comprising applying a separating light before separating the 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 template and the cured liquid.

46. The method of claim 42, further comprising providing an enclosure around at least the template and the substrate and inhibiting temperature variations greater than about 1.0°

C. within at least a portion of the enclosure.

47. The method of claim 42, wherein the activating light curable liquid has a viscosity of less than about 30 centipoise measured at 25°

C.

48. The method of claim 42, wherein at least a portion of a surface of the patterned template comprises a surface treatment layer.

49. The method of claim 42, further comprising determining a distance between the template and the substrate by sensing a resistive force between the template and the activating light curable liquid.

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

applying a predetermined volume of an activating light curable liquid to a portion of a patterned template;

positioning the patterned template and the substrate in a spaced relation to each other so that a gap is created between the template and the substrate, wherein the gap is established such that the activating light curable liquid contacts substantially an entirety of a patterning area of the template but does not extend past a perimeter of the patterning area;

applying an activating light to the activating light curable liquid, wherein the application of the activating light substantially cures the activating light curable liquid, forming a first patterned area of a cured liquid; and

separating the template from the cured liquid.

51. The method of claim 50, further comprising:

applying an additional predetermined volume of the activating light curable liquid to the template in an additional predetermined pattern, wherein the additional predetermined pattern does not cover an entirety of a patterning area of the template;

positioning the template and the substrate in a spaced relation to each other so that a second area of the substrate to be patterned is over the template, and so that an additional gap is created between the template and the substrate, wherein the additional gap is established such that the activating light curable liquid contacts substantially an entirety of an additional patterning area of the template but does not extend past a perimeter of the additional patterning area; and

applying activating light to the activating light curable liquid, wherein the application of the activating light substantially cures the activating light curable liquid, forming a second patterned area.

52. The method of claim 50, further comprising applying a separating light before separating the 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 template to the cured liquid is reduced.

53. The method of claim 50, further comprising applying a separating light before separating the 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 template and the cured liquid.

54. The method of claim 50, further comprising providing an enclosure around at least the template and the substrate and inhibiting temperature variations greater than about 1.0°

C. within at least a portion of the enclosure.

55. The method of claim 50, wherein the activating light curable liquid has a viscosity of less than about 30 centipoise measured at 25°

C.

56. The method of claim 50, wherein at least a portion of a surface of the patterned template comprises a surface treatment layer.

57. The method of claim 50, further comprising determining a distance between the template and the substrate by sensing a resistive force between the template and the activating light curable liquid.

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

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

C.;

positioning a patterned template and the substrate in a spaced relation to each other so that a gap is created between the template and the substrate, wherein the gap is established such that the activating light curable liquid contacts substantially an entirety of a patterning area of the patterned template but does not extend past a perimeter of the patterning area;

applying an activating light to the activating light curable liquid, wherein the application of the activating light substantially cures the activating light curable liquid, forming a first patterned area of a cured liquid; and

separating the patterned template from the cured liquid.

59. The method of claim 58, further comprising:

applying an additional predetermined volume of the activating light curable liquid to a second portion of the substrate in an additional predetermined pattern;

positioning the patterned template and the substrate in a spaced relation to each other so that an additional gap is created between the patterned template and the substrate, wherein the additional gap is established such that the activating light curable liquid contacts substantially an entirety of an additional patterning area of the template but does not extend past a perimeter of the additional patterning area; and

applying the activating light to the activating light curable liquid on the second portion of the substrate, wherein the application of the activating light substantially cures the activating light curable liquid on the second portion of the substrate, forming a second patterned area.

60. The method of claim 58, further comprising applying a separating light before separating the 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 template to the cured liquid is reduced.

61. The method of claim 58, further comprising applying a separating light before separating the 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 template and the cured liquid.

62. The method of claim 58, further comprising providing an enclosure around at least the template and the substrate and inhibiting temperature variations greater than about 1.0°

C. within at least a portion of the enclosure.

63. The method of claim 58, wherein at least a portion of a surface of the patterned template comprises a surface treatment layer.

64. The method of claim 58, further comprising determining a distance between the template and the substrate by sensing a resistive force between the template and the activating light curable liquid.

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

applying a predetermined volume of an activating light curable liquid to a first portion of the substrate in a predetermined pattern;

positioning a patterned template and the substrate in a spaced relation to each other so that a gap is created between the template and the substrate, wherein the gap is established such that the activating light curable liquid contacts substantially an entirety of a patterning area of the template but does not extend past a perimeter of the patterning area;

applying an activating light to the activating light curable liquid, wherein the application of the activating light substantially cures the activating light curable liquid, forming a first patterned area of a cured liquid; and

separating the template from the cured liquid.

66. The method of claim 65, further comprising applying a separating light before separating the 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 template to the cured liquid is reduced.

67. The method of claim 65, further comprising applying a separating light before separating the 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 template and the cured liquid.

68. The method of claim 65, further comprising providing an enclosure around at least the template and the substrate and inhibiting temperature variations greater than about 1.0°

C. within at least a portion of the enclosure.

69. The method of claim 65, wherein at least a portion of a surface of the patterned template comprises a surface treatment layer.

70. The method of claim 65, further comprising determining a distance between the template and the substrate by sensing a resistive force between the template and the applied activating light curable liquid.

71. A method of patterning differing regions of a substrate with a template, with a subset of said differing regions having a perimeter associated therewith, the method comprising:

for said subset of said differing regions, sequentially positioning a predetermined volume of a polyermizable fluid on one of said substrate and said template, defining a gap between said template and said substrate, with said predetermined volume substantially filling said gap while being maintained within said perimeter.