Two-dimensional arrays of holes with sub-lithographic diameters formed by block copolymer self-assembly

• US 8,512,846 B2
• Filed: 05/14/2012
• Issued: 08/20/2013
• Est. Priority Date: 01/24/2007
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Millward, Dan B.
• Primary Examiner(s): CAIN, EDWARD J
• Application Number:
  US13/470,503
• Publication Number:
  US 20120263915A1
• Time in Patent Office: 463 Days
• Field of Search: 428/105, 428/113, 977/778, 977/784, 977/789, 977/790
• US Class Current: 428/105
• 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: H01L 21/67103 mainly by conduction
• CPC Class Codes: H05B 3/145 Carbon only, e.g. carbon black, graphite
• CPC Class Codes: H05B 3/24 heating conductor being self-supporting
• CPC Class Codes: Y10T 29/49083 Heater type
• CPC Class Codes: Y10T 428/24058 including grain, strips, or filamentary elements in respective layers or components in angular relation
• CPC Class Codes: Y10T 428/24124 Fibers
• CPC Class Codes: Y10T 428/24174 including sheet or component perpendicular to plane of web or sheet
• CPC Class Codes: Y10T 428/24182 Inward from edge of web or sheet

Abstract

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

Claims

1. A method of fabricating a polymeric material, the method comprising:

masking a neutral wetting material situated on a preferential wetting substrate to form masked and unmasked sections, each unmasked section having a width of about L_o, and each masked section having a width of about nL_o;

removing the unmasked sections of the neutral wetting material to expose the preferential wetting substrate;

removing the mask to expose the sections of the neutral wetting material;

forming an overlying material over the sections of the preferential wetting substrate and the neutral wetting material;

forming a plurality of trenches in the overlying material to expose the sections of the preferential wetting substrate and the neutral wetting material oriented perpendicular to sidewalls of the trenches, each trench having preferential wetting sidewalls and ends, a width of about L_o, a length of about m*(n+1)−

*L_o, where m is a number of sections of the preferential wetting substrate, n is a number of perpendicularly oriented cylinders, and m and n are independently 1-50, the ends of the trenches being aligned, and a pitch distance between adjacent trenches of at least about 2*L_o;

forming a block copolymer material within the trenches; and

causing the block copolymer material to self-assemble into cylinders of a first polymer block of the block copolymer material in a matrix of a second polymer block within each trench, the cylinders situated on the sections of the neutral wetting material in a perpendicular orientation to the preferential wetting substrate, and the cylinders situated on the sections of the preferential wetting substrate in a parallel orientation to the preferential wetting substrate, each trench containing m rows of n cylinders with the cylinders within each trench at a pitch distance of about L_o and the cylinders between adjacent trenches at a pitch distance of about 2*L_o.

2. The method of claim 1, wherein the block copolymer material comprises from about 60:

40 to about 80;

20 ratio of the first polymer block to the second polymer block.

3. The method of claim 1, wherein the block copolymer material comprises a blend of the block copolymer material and a homopolymer of the first polymer block, the second polymer block, or both.

4. The method of claim 1, wherein the block copolymer material within the trenches has a thickness of about L_o.

5. The method of claim 1, further comprising forming the neutral wetting material on the preferential wetting substrate.

6. The method of claim 1, wherein the neutral wetting material comprises a random copolymer.

7. The method of claim 1, wherein the neutral wetting material comprises hydrogen-terminated silicon.

8. The method of claim 1, wherein the preferential wetting substrate comprises silicon.

9. The method of claim 1, further comprising applying a preferential wetting material to the ends and sidewalls of the trenches.

10. The method of claim 1, wherein the sidewalls and ends of the trenches comprise a preferential wetting material selected from the group consisting of silicon oxide, silicon nitride, silicon oxycarbide, metal, and resist material.

11. The method of claim 1, wherein the block copolymer material on the sections of the neutral wetting material self-assembles into a single row of perpendicularly oriented cylinders.

12. The method of claim 1, wherein causing the block copolymer material to self-assemble comprises thermally annealing the block copolymer material.

13. The method of claim 1, wherein causing the block copolymer material to self-assemble comprises solvent annealing the block copolymer material.

14. The method of claim 1, further comprising, after causing the block copolymer material to self-assemble, selectively removing the first polymer block to provide openings within the matrix of the second polymer block.

15. The method of claim 14, further comprising, prior to selectively removing the first polymer block, crosslinking the self-assembled block copolymer.

16. The method of claim 14, further comprising etching the preferential wetting substrate through the openings.

17. A method of fabricating a polymeric material, the method comprising:

forming a plurality of trenches in a material overlying a substrate, each trench having a preferential wetting floor, sidewalls and ends, a width of about L_o and a length, the ends of the trenches being aligned, a pitch distance between adjacent trenches being at least about 2*L_o;

forming a neutral wetting material onto the preferential wetting floor of the trench;

masking the neutral wetting material to form masked and unmasked sections oriented perpendicular to sidewalls of the trenches, each unmasked section having a width of about L_o, each masked section having a width of about nL_o;

removing the unmasked sections of the neutral wetting material to expose sections of the preferential wetting floor of the trench;

removing the mask to expose sections of the neutral wetting material;

forming a block copolymer material within the trenches; and

causing the block copolymer material to self-assemble into cylinders in a polymer matrix within each trench, the cylinders situated on the sections of the neutral wetting material in a perpendicular orientation to the substrate, cylinders situated on the sections of the preferential wetting floor of the trench in a parallel orientation to the substrate, each trench containing m rows of n cylinders with the cylinders within each trench at a pitch distance of about L_o and the cylinders between adjacent trenches at a pitch distance of about 2*L_o.

18. The method of claim 17, wherein the length of the trenches is about m*(n+1)−

*L_o, where m is a number of sections of the preferential wetting floor of the trenches, n is a number of perpendicularly oriented cylinders, and m and n are independently 1 to 50.

19. A polymeric material situated within adjacently spaced apart trenches, ends of the trenches being aligned, the polymeric material comprising a rectangular array of perpendicularly oriented cylindrical domains of a first block of a block copolymer within a matrix of a second block of the block copolymer, the perpendicularly oriented cylindrical domains within each trench in a single array at a pitch distance of about L_o and aligned with the cylindrical domains in adjacent trenches at a pitch distance of about 2*L_o.

20. A polymeric material comprising a rectangular array of perpendicularly oriented cylindrical domains of a first block of a block copolymer within a matrix of a second block of the block copolymer, the perpendicularly oriented cylindrical domains in one dimension at a pitch distance of about L_o and aligned with perpendicularly oriented cylindrical domains in a second dimension at a pitch distance of about 2*L_o.

21. A polymeric material comprising a square array of perpendicularly oriented cylindrical domains of a first block of a block copolymer within a matrix of a second block of the block copolymer, the perpendicularly oriented cylindrical domains in a single array at a pitch distance of about L_o and aligned with adjacent perpendicularly oriented cylindrical domains at a pitch distance of about L_o.

22. A polymeric material comprising a square array of perpendicularly oriented cylindrical domains of a first block of a block copolymer within a matrix of a second block of the block copolymer, the perpendicularly oriented cylindrical domains in a first dimension in a single row at a pitch distance of about L_o and aligned with perpendicularly oriented cylindrical domains in a second dimension at a pitch distance of about L_o.

23. A polymeric material comprising an annealed block copolymer material within adjacently spaced apart trenches, ends of the trenches being aligned, the annealed block copolymer material comprising a rectangular array of cylindrical domains of a first block of the block copolymer material within a matrix of a second block of the block copolymer material, the cylindrical domains within each trench in a single array at a pitch distance of about L_o and aligned with the cylindrical domains in adjacent trenches at a pitch distance of about 2*L_o, wherein the single array within each trench comprises n perpendicularly oriented cylinders between two parallel-oriented cylinders.

24. A polymeric material comprising a rectangular array of cylindrical domains of a first block of a block copolymer within a matrix of a second block of the block copolymer, the cylindrical domains in a first dimension comprising n perpendicularly oriented cylinders between two parallel-oriented cylinders in a single row at a pitch distance of about L_o, the cylindrical domains in the first dimension aligned with cylindrical domains in a second dimension at a pitch distance of about 2*L_o.