Graphoepitaxial Self-Assembly of Arrays of Downward Facing Half-Cylinders

• US 20090274887A1
• Filed: 05/02/2008
• Published: 11/05/2009
• Est. Priority Date: 05/02/2008
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Westmoreland, Donald, Millward, Dan B.
• Granted Patent: US 8,114,301 B2
• Time in Patent Office: Days
• US Class Current: 428/221
• CPC Class Codes: B81C 1/00031 Regular or irregular arrays of nanoscale structures, e.g. etch mask layer photomechanical, e.g. photolithographic, production of textured or patterned surfaces G03F7/00; lithographic processes for making patterned surfaces using printing and stamping G03F7/0002
• CPC Class Codes: B81C 2201/0149 Forming nanoscale microstructures using auto-arranging or self-assembling material
• CPC Class Codes: B81C 2201/0198 for making a masking layer
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• 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 21/02118 carbon based polymeric organic or inorganic material, e.g. polyimides, poly cyclobutene or PVC polymers per se C08G, photoresist per se G03F
• CPC Class Codes: H01L 21/0223 formation by oxidation, e.g. oxidation of the substrate
• CPC Class Codes: H01L 29/06 characterised by their shape; characterised by the shapes, relative sizes, or dispositions of the semiconductor regions ; characterised by the concentration or distribution of impurities within semiconductor regions
• CPC Class Codes: H01L 29/0657 characterised by the shape of the body
• CPC Class Codes: Y10S 438/947 Subphotolithographic processing
• CPC Class Codes: Y10S 977/888 Shaping or removal of materials, e.g. etching
• CPC Class Codes: Y10S 977/895 having step or means utilizing chemical property
• CPC Class Codes: Y10S 977/90 having step or means utilizing mechanical or thermal property, e.g. pressure, heat
• CPC Class Codes: Y10T 428/24182 Inward from edge of web or sheet
• CPC Class Codes: Y10T 428/24521 with component conforming to contour of nonplanar surface
• CPC Class Codes: Y10T 428/2462 with partial filling of valleys on outer surface
• CPC Class Codes: Y10T 428/249921 Web or sheet containing structurally defined element or component

Abstract

Methods for fabricating sublithographic, nanoscale microstructures in line arrays utilizing self-assembling block copolymers, and films and devices formed from these methods are provided.

Claims

1. A method of forming a nanostructured polymer material on a substrate, comprising:

forming a self-assembling block copolymer material within a trench in a material layer on the substrate, the trench having a length, a neutral wetting floor, and opposing sidewalls and ends that are preferentially wetting to a minority block of the block copolymer;

applying a material preferentially wetting to the minority block over and in contact with the block copolymer material within the trench; and

annealing the block copolymer material such that the block copolymer material self-assembles into half-cylindrical domains of the minority block of the block copolymer within a matrix of a majority block of the block copolymer, the half-cylindrical polymer domains oriented parallel to the trench floor and extending the length of the trench, the half-cylindrical domains having a face oriented toward and wetting the neutral wetting trench floor.

2. The method of claim 1, wherein the minority block of the block copolymer comprises a metal.

3. The method of claim 2, wherein the metal is selected from the group consisting of silicon, chromium, titanium, aluminum, molybdenum, gold, platinum, ruthenium, zirconium, tungsten, vanadium, lead, and zinc.

4. The method of claim 2, wherein the minority block of the block copolymer is selected from the group consisting of poly(vinylpyridine), poly(methylmethacrylate), poly(lactide), poly(tert-butyl acrylate) poly(ethylene-co-butylene), poly(ethylene oxide), poly(butadiene), and polystyrene.

5. The method of claim 2, wherein the minority block of the block copolymer is selected from the group consisting of polydimethylsiloxane, poly(vinylmethylsiloxane), and poly(ferrocenylmethylethylsilane).

6. The method of claim 1, wherein the majority block of the block copolymer is selected from the group consisting of poly(styrene), poly(isoprene), poly(butadiene), and poly(ethylene-alt-propylene), and poly(methylmethacrylate).

7. The method of claim 1, wherein applying the preferentially wetting material comprises contacting the block copolymer material within the trench with an elastomeric material.

8. The method of claim 7, wherein the preferentially wetting material comprises poly(dimethylsiloxane) or poly(urethane).

9. The method of claim 8, wherein the preferentially wetting material comprises poly(dimethylsiloxane) having a hydrophilic surface.

10. The method of claim 9, wherein the preferentially wetting material comprises poly(dimethylsiloxane) comprising silanol groups on a surface.

11. The method of claim 1, wherein applying the preferentially wetting material comprises depositing an inorganic material to form a layer over the block copolymer material within the trench.

12. The method of claim 11, wherein the preferentially wetting material comprises a spin-on dielectric material.

13. The method of claim 1, further comprising removing the preferentially wetting material to expose the annealed block copolymer material within the trench.

14. The method of claim 13, wherein removing the preferentially wetting material comprises separating the preferentially wetting material from the annealed block copolymer material.

15. The method of claim 14, further comprising, applying a solvent to the preferentially wetting material to enhance removal.

16. The method of claim 13, wherein the preferentially wetting material comprises an oxide material and removing the preferential wetting material layer comprises applying a fluoride-based etchant.

17. The method of claim 1, further comprising selectively removing the majority polymer block to expose the half-cylindrical domains and the substrate adjacent to said half-cylindrical domains.

18. The method of claim 1, further comprising selectively removing polymeric material to expose the substrate and forming a metal component of the minority block into an inorganic metal material such that said inorganic metal material forms a line on the substrate.

19. A method of forming a nanostructured polymer material on a substrate, comprising:

forming a block copolymer material within a trench in a material layer overlying the substrate, the trench having a width, a length, a depth, a neutral wetting floor, and opposing sidewalls and ends that are preferentially wetting to a minority block of the block copolymer;

applying a material preferentially wetting to the minority block over and in contact with the block copolymer material within the trench; and

causing a microphase separation in the block copolymer material to form a half-cylinder domain comprising the minority block of the block copolymer in a matrix of a majority block of the block copolymer, the half-cylinder domain polymer domain oriented parallel to the trench floor and registered to the sidewalls in a line extending the length of the trench, the half-cylinder polymer domain having a face situated on the neutral wetting trench floor.

20. The method of claim 19, wherein the trench has a width of about 1.5-2 times the L value of the block copolymer, and a single half-cylinder domain is formed within the trench having a width of about 0.5*L.

21. The method of claim 19, wherein the trench has a width greater than about 2 times the L value of the block copolymer, and two or more half-cylinder domains are formed within the trench at a center-to-center distance of about the L value of the block copolymer.

22. The method of claim 21, wherein the trench has a width of about 3 or more times the L value of the block copolymer.

23. The method of claim 19, wherein the neutral wetting floor comprises a blend of grafted homopolymers.

24. A method of forming a nanostructured polymer material on a substrate, comprising:

forming a self-assembling block copolymer material within a trench in a material layer on the substrate, the trench having a length, a neutral wetting floor, and opposing sidewalls and ends that are preferentially wetting to a minority block of the block copolymer;

applying an atmosphere preferentially wetting to the minority block over and in contact with the block copolymer material within the trench; and

annealing the block copolymer material such that the block copolymer material self-assembles into half-cylindrical domains of the minority block of the block copolymer within a matrix of a majority block of the block copolymer, the half-cylindrical polymer domains oriented parallel to the trench floor and extending the length of the trench, the half-cylindrical domains having a face oriented toward and wetting the neutral wetting trench floor, and the minority block forming a layer over the block copolymer material.

25. The method of claim 24, wherein the preferentially wetting atmosphere is selected from the group consisting of clean dry air, humid air, and a near-saturated solvent atmosphere.

26. A method of etching a substrate, comprising:

forming a self-assembling block copolymer material within a trench in a material layer on the substrate, the trench having a length, a neutral wetting floor, and opposing sidewalls and ends that are preferentially wetting to a minority block of the block copolymer;

applying a material preferentially wetting to the minority block over and in contact with the block copolymer material within the trench;

annealing the block copolymer material such that the block copolymer material self-assembles into half-cylindrical domains of the minority block of the block copolymer within a matrix of a majority block of the block copolymer, the half-cylindrical polymer domains oriented parallel to the trench floor and extending the length of the trench, the half-cylindrical domains having a face oriented toward and wetting the neutral wetting trench floor;

further comprising removing the preferentially wetting material to expose the annealed block copolymer material within the trench;

selectively removing the majority polymer block to expose the substrate wherein at least at portion of the half-cylindrical domains remains as a continuous line on said substrate; and

etching exposed portions of the substrate to form a trench therein.

27. The method of claim 26, wherein the minority block comprises a metal, and removing the majority block further comprises removing the minority polymer block and forming the metal into an inorganic metal material as a line on the substrate.

28. The method of claim 26, further comprising filling the trench with a fill material.

29. The method of claim 28, wherein the fill material comprises a metal or a metal alloy.

30. The method of claim 28, wherein the fill material comprises an insulator material.

31. A method of etching a substrate, comprising:

forming a self-assembling block copolymer material within a trench in a material layer on the substrate, the trench having a length, a neutral wetting floor, and opposing sidewalls and ends that are preferentially wetting to a minority block of the block copolymer;

applying an atmosphere preferentially wetting to the minority block over and in contact with the block copolymer material within the trench; and

annealing the block copolymer material such that the block copolymer material self-assembles into half-cylindrical domains of the minority block of the block copolymer within a matrix of a majority block of the block copolymer, the half-cylindrical polymer domains oriented parallel to the trench floor and extending the length of the trench, the half-cylindrical domains having a face oriented toward and wetting the neutral wetting trench floor, and the minority block forming a layer overlying the block copolymer material.

comprising removing said overlying layer of the minority block to expose the annealed block copolymer material within the trench;

selectively removing the majority polymer block to expose the substrate wherein at least at portion of the half-cylindrical domains remains as a continuous line on said substrate; and

etching exposed portions of the substrate to form a trench therein.

32. A polymeric material situated within a trench in a material layer overlying a substrate, the trench having sidewalls, ends, a floor, a width and a length, the polymeric material comprising a self-assembled block copolymer material comprising half-cylinder polymer domains of a minority polymer block in a matrix of a majority polymer block, the half-cylinder polymer domains oriented parallel to the trench floor and extending the length of the trench, the half-cylindrical domains having a face situated on the trench floor.

33. The polymeric material of claim 32, wherein the trench floor comprises a neutral wetting material, and the sidewalls and ends comprise a material preferentially wetting to the minority polymer block.

34. The polymer material of claim 32, further comprising a material preferentially wetting to the minority block overlying the polymeric material.

35. The polymer material of claim 32, wherein the minority block selectively comprises a metal.