Graphoepitaxial self-assembly of arrays of downward facing half-cylinders

• US 8,518,275 B2
• Filed: 02/14/2012
• Issued: 08/27/2013
• Est. Priority Date: 05/02/2008
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Millward, Dan B., Westmoreland, Donald
• Primary Examiner(s): ALANKO, ANITA KAREN
• Application Number:
  US13/396,039
• Publication Number:
  US 20120138570A1
• Time in Patent Office: 560 Days
• Field of Search: None
• US Class Current: 216/2
• 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 sub-lithographic, 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 etching a substrate, comprising:

applying a material over and in contact with a block copolymer material within a trench in a material layer on a substrate, the material being preferentially wetting to a minority block of the block copolymer material, the trench having a length, a neutral wetting floor, and opposing sidewalls and ends that are preferentially wetting to the minority block of the block copolymer material;

annealing the block copolymer material to form one or more lines of half cylinders of the minority block within the trench within a matrix of a majority block of the block copolymer material, the one or more lines of half cylinders extending the length of the trench and oriented parallel to the neutral wetting floor, with a face oriented toward and wetting the neutral wetting floor;

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

selectively removing the majority block to expose the substrate wherein at least a portion of the one or more lines of half cylinders remains as a continuous line on the substrate; and

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

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

3. The method of claim 2, further comprising removing the minority block and forming the metal into an inorganic metal material as a line on the substrate.

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

5. 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.

6. The method of claim 5, wherein the preferentially wetting material comprises an oxide material.

7. The method of claim 1, wherein the preferentially wetting material is a preferentially wetting atmosphere selected from the group consisting of dry air, humid air, and a near-saturated solvent atmosphere.

8. The method of claim 7, wherein the preferentially wetting atmosphere is a near-saturated solvent atmosphere comprising ethanol or dimethylformamide.

9. The method of claim 1, further comprising, after removing the preferentially wetting material, removing a layer of the minority block overlying a surface of the annealed block copolymer material within the trench.

10. The method of claim 1, wherein the trench has a width of about 1.5-2 times the L value of the block copolymer material, and a single line of half cylinders having a width of about 0.5 times the L value is formed within the trench.

11. The method of claim 1, wherein the trench has a width greater than about two times the L value of the block copolymer material, and two or more lines of half cylinders are formed within the trench at a center-to-center distance of about the L value of the block copolymer material.

12. The method of claim 11, wherein the trench has a width of about three or more times the L value of the block copolymer material.

13. The method of claim 1, further comprising filling the trench with a fill material.

14. The method of claim 13, wherein the fill material comprises a metal or a metal alloy.

15. The method of claim 13, wherein the fill material comprises an insulator material.

16. A method of etching a substrate, comprising:

applying an atmosphere over and in contact with a block copolymer material within a trench in a material layer on the substrate, the atmosphere being preferentially wetting to a minority block of the block copolymer material, the trench having a length, a neutral wetting floor, and opposing sidewalls and ends that are preferentially wetting to the minority block of the block copolymer material;

annealing the block copolymer material to form one or more lines of half cylinders of the minority block within the trench within a matrix of a majority block of the block copolymer material, the one or more lines of half cylinders extending the length of the trench and oriented parallel to the neutral wetting floor, with a face oriented toward and wetting the neutral wetting floor;

selectively removing the majority block to expose the substrate wherein at least a portion of the one or more lines of half cylinders remains as a continuous line on the substrate; and

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

17. The method of claim 16, wherein annealing the block copolymer material comprises forming a layer of the minority block over the block copolymer material.

18. The method of claim 17, further comprising removing the layer of the minority block to expose the annealed block copolymer material within the trench.

19. The method of claim 16, wherein the preferentially wetting atmosphere is selected from the group consisting of clean dry air, humid air, and a near-saturated solvent atmosphere.