Method of forming stepped structures employing imprint lithography

• US 20040211754A1
• Filed: 04/25/2003
• Published: 10/28/2004
• Est. Priority Date: 04/25/2003
• Status: Active Grant

• Current Assignee: Mii Newco, Inc.
• Original Assignee: Molecular Imprints, Inc. (Canon Inc.)
• Inventors: Sreenivasan, Sidlgata V.
• Granted Patent: US 7,396,475 B2
• Time in Patent Office: Days
• US Class Current: 216/41
• 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 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: C03C 17/002 for flat glass, e.g. float glass
• CPC Class Codes: C03C 23/0005 by irradiation
• CPC Class Codes: C03C 23/002 by ultraviolet light
• 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 21/76813 involving a partial via etch
• CPC Class Codes: H01L 21/76817 using printing or stamping techniques

Abstract

The present invention provides a method for forming a stepped structure on a substrate that features transferring, into the substrate, an inverse shape of the stepped structure disposed on the substrate.

Claims

1. A method of forming a stepped-structure on a substrate, said method comprising:

forming, on said substrate, a multi-tiered structure having a shape; and

transferring an inverse of said shape into said substrate.

2. The method as recited in claim 1 wherein transferring further includes transferring said inverse of said shape into said substrate to form a via portion and a trench portion, with dimensions of said via portion being established as a function of dimensions of a first sub-portion of said multi-tiered structure and dimensions of said trench portion being established as a function of dimensions of a second sub-portion of said multi-tiered structure.

3. The method as recited in claim 1 wherein transferring further includes covering, with an etch selectivity layer, said multi-tiered structure, with said substrate, said etch selectivity layer and said multi-tiered structure defining a multi-layered structure and removing portions of said multi-layered structure to expose regions of said substrate in superimposition with a first sub-portion of said multi-tiered structure while forming a hard mask in areas of said etch selectivity layer in superimposition with a second sup-portion of said multi-tiered structure.

4. The method as recited in claim 1 wherein transferring further includes covering, with an etch selectivity layer, said multi-tiered structure, and said etch selectivity layer, said substrate, said multi-tiered structure defining a multi-layered structure and subjecting said multi-layered structure to etch processes that sequentially remove first and second batches of material from said multi-layered structure, with said first batch of material corresponding to a first sub-portion of said multi-tiered structure, first portions of said etch selectivity layer in superimposition therewith and portions of said multi-tiered structure and said substrate superimposed by a first sub-portion of said multi-tiered structure and said second batch of material corresponding to said shoulders, second portions of said etch selectivity layer in superimposition therewith and said second portions of said multi-tiered structure and said substrate superimposed by said shoulders.

5. The method as recited in claim 1 wherein forming further includes depositing a polymerizable fluid composition on said substrate and contacting said composition with a mold having a relief structure including a shape complementary to said shape of said multi-tiered structure and exposing said composition to actinic radiation to polymerize said composition.

6. The method as recited in claim 1 wherein forming further includes forming said multi-tiered structure from an organic polymerizable material substantially free of silicon and covering further includes forming said etch selectivity layer from a silicon-containing material.

7. The method as recited in claim 1 wherein forming further includes forming said multi-tiered structure from a material having a polymerizable compound and a surfactant having a surface energy that is less than a surface energy of said polymerizable compound.

8. The method as recited in claim 1 wherein covering further includes forming said etch selectivity layer from a material having a polymerizable compound and a surfactant having a surface energy that is lower than a surface energy of said polymerizable compound.

9. The method as recited in claim 1 wherein covering further includes forming said etch selectivity layer by disposing, on said multi-tiered structure, a polymerizable fluid composition and contacting said polymerizable fluid composition with a mold having a substantially smooth surface and subjecting said polymerizable fluid composition to conditions to polymerize said polymerizable fluid composition.

10. The method as recited in claim 1 wherein covering further includes disposing said etch selectivity layer by spin-coating a silicon-containing material on said multi-tiered structure.

11. The method as recited in claim 1 further including forming, on said substrate, an etch stop layer positioned between said substrate and said multi-tiered structure.

12. The method as recited in claim 1 further including depositing in said via portion and said trench portion, a conductive material.

13. The method as recited in claim 1 wherein said multi-tiered structure includes a stepped recess.

14. The method as recited in claim 13 further including forming said substrate from a wafer and a film layer and wherein transferring further includes transferring said inverse of said shape into said film layer.

15. The method as recited in claim 13 further including forming said substrate from said wafer and said film layer and wherein transferring further includes transferring said inverse of said shape into said wafer.

16. The method as recited in claim 1 wherein said multi-tiered structure includes a bi-level protrusion including a projection and shoulders, with said projection having an apex surface and said shoulders being spaced-apart from said apex surface and said substrate.

17. The method as recited in claim 16 further including forming said substrate from said wafer and said film layer and wherein transferring further includes transferring said inverse of said shape into said film layer.

18. The method as recited in claim 16 further including forming said substrate from said wafer and said film layer and wherein transferring further includes transferring said inverse of said shape into said wafer.

19. A method of forming a stepped-structure on a substrate, said method comprising:

forming, on said substrate, a multi-tiered structure;

covering, with an etch selectivity layer, said multi-tiered structure, with said substrate, said etch selectivity layer and said multi-tiered structure defining a multi-layered structure;

defining regions of said substrate to be etched as a function of portions of multi-tiered structure exposed by removal of said etch selectivity layer.

20. The method as recited in claim 19 wherein forming further includes forming said multi-tiered structure with a projection and shoulders and defining said regions further includes concurrently removing portions of said multi-layered structure to form a via portion in a region of said substrate in superimposition with a projection while forming a hard mask in areas of said etch selectivity layer in superimposition with said shoulders by exposing said multi-layered structure to a plasma etch.

21. The method as recited in claim 19 wherein forming further includes depositing a polymerizable fluid composition on said substrate and contacting said composition with a mold having a relief structure including a shape complementary to a shape of said multi-tiered structure and exposing said composition to actinic radiation to polymerize said composition.

22. The method as recited in claim 19 wherein forming further includes forming said multi-tiered structure from an organic polymerizable material substantially free of silicon and covering further includes forming said etch selectivity layer from a silicon-containing material.

23. The method as recited in claim 21 wherein covering further includes forming said etch selectivity layer by disposing, on said multi-tiered structure, said polymerizable fluid composition and contacting said polymerizable fluid composition with a mold having a substantially smooth surface and subjecting said polymerizable fluid composition to conditions to polymerize said polymerizable fluid composition.

24. The method as recited in claim 21 wherein covering further includes disposing said etch selectivity layer by spin-coating said silicon-containing material on said multi-tiered structure.

25. The method as recited in claim 21 wherein forming further includes forming said multi-tiered structure from a material having a polymerizable compound and a surfactant having a surface energy that is less than a surface energy of said polymerizable compound.

26. The method as recited in claim 21 wherein covering further includes forming said etch selectivity layer from a material having a polymerizable compound and a surfactant having a surface energy that is lower than a surface energy of said polymerizable compound.

27. The method as recited in claim 19 wherein said multi-tiered structure includes a stepped recess having a shape.

28. The method as recited in claim 27 further including forming said substrate from a wafer and a film layer and transferring an inverse of said shape into said film layer.

29. The method as recited in claim 27 further including forming said substrate from said wafer and said film layer and wherein transferring further includes transferring said inverse of said shape into said wafer.

30. The method as recited in claim 19 wherein said multi-tiered structure includes a bi-level protrusion including a projection and shoulders, with said projection having an apex surface and said shoulders being spaced-apart from said apex surface and said substrate, said bi-level protrusion defining a shape.

31. The method as recited in claim 30 further including forming said substrate from said wafer and said film layer and wherein transferring further includes transferring said inverse of said shape into said film layer.

32. The method as recited in claim 31 further including forming said substrate from said wafer and said film layer and wherein transferring further includes transferring said inverse of said shape into said wafer.

33. A method of forming a stepped structure on a substrate, said method comprising:

forming a patterned layer on said substrate having a bi-level protrusion including a projection and shoulders, said projection having an apex surface with said shoulders being spaced-apart from said apex surface and said substrate;

covering said projection with an etch selectivity layer;

creating a crown surface by removing a portion of said etch selectivity layer to expose said apex surface, with remaining portions of said bi-level protrusion remaining covered by said etch selectivity layer;

removing said apex surface and material of said patterned layer in superimposition with said apex surface while avoiding exposure of remaining portions of said bi-level protrusion;

removing areas of said etch selectivity layer in superimposition with said remaining portions of said bi-level protrusion to expose said shoulders; and

removing said shoulders and said patterned layer in superimposition therewith.

34. The method as recited in claim 33 wherein forming further includes depositing a polymerizable fluid composition on said substrate and contacting said composition with a mold having a relief structure including a shape complementary to a shape of said bi-level protrusion and exposing said composition to actinic radiation to polymerize said composition.

35. The method as recited in claim 33 wherein forming further includes forming said patterned layer from an organic polymerizable material substantially free of silicon and covering further includes forming said etch selectivity layer from a silicon-containing material.

36. The method as recited in claim 35 wherein removing said apex surface further includes subjecting said crown surface to an etch chemistry that is highly reactive with material from which said bi-level protrusion is formed and forms a hard mask in the region of said crown surface that comprises material from which said etch selectivity layer is formed.

37. The method as recited in claim 35 wherein covering further includes forming said etch selectivity layer by disposing, on said patterned layer, a polymerizable fluid composition and contacting said polymerizable fluid composition with a mold having a substantially smooth surface and subjecting said polymerizable fluid composition to conditions to polymerize said polymerizable fluid composition.

38. The method as recited in claim 35 wherein covering further includes disposing said etch selectivity layer by spin-coating a silicon-containing material on said patterned layer.

39. The method as recited in claim 35 wherein forming further includes forming said patterned layer from a material having a polymerizable compound and a surfactant having a surface energy that is less than a surface energy of said polymerizable compound.

40. The method as recited in claim 35 wherein covering further includes forming said etch selectivity layer from a material having a polymerizable compound and a surfactant having a surface energy that is lower than a surface energy of said polymerizable compound.