Block copolymers and lithographic patterning using same

Patent metadata

Field	Value
Publication number	US-9541830-B2
Application number	US-201214342657-A
Country	US
Kind code	B2
Filing date	Sep 6, 2012
Priority date	Sep 6, 2011
Publication date	Jan 10, 2017
Grant date	Jan 10, 2017

Abstract

Block copolymers and methods of making patterns of organic thin films using the block copolymers. The block copolymers comprise a fluorinated block. Thin films of the block copolymers have microdomains that can be aligned. As a result the patterns of organic thin films having smaller dimensions than the pattern of incident deep-UV or e-beam radiation can be formed. For example, the block copolymers can be used in lithography, filtration, and templating applications.

First claim

What is claimed is:

1. A method of forming a patterned organic thin film comprising the steps of:
a) providing a substrate;
b) forming a thin film of a block copolymer comprising a positive-tone polymer block and a negative-tone polymer block on the substrate, wherein the thin film has periodic microdomains;
c) aligning the periodic microdomains of the thin film;
d) exposing at least a portion of the thin film from b) to deep-UV or e-beam radiation to differentially affect the positive-tone polymer blocks and negative-tone polymer blocks in the exposed portion of the thin film such that an exposed pattern, and, optionally, an unexposed portion, of thin film is/are formed; and
e) exposing the thin film from d) to a solvent such that the unexposed portion of block copolymer thin film, if present, and selected regions of the exposed portion of the thin film are removed, and a patterned organic thin film of the negative-tone polymer blocks or a patterned organic thin film of the positive-tone polymer blocks is formed.

2. The method of claim 1 , wherein the negative-tone block comprises at least one crosslinkable moiety, in step d) the positive-tone polymer blocks are degraded and negative-tone polymer blocks are crosslinked, and in step e) the patterned organic thin film of the negative-tone polymer blocks is formed.

3. The method of claim 1 , wherein the block copolymer further comprises one, two, or three additional blocks.

4. The method of claim 1 , wherein the block copolymer has the following structure:

wherein the A block is the negative-tone block selected from polystyrene block, polyhydroxystyrene block, substituted analog thereof, and a mixture thereof and the B block is the positive-tone block and is a fluorinated block comprising at least one fluorinated monomer, and
wherein x and y are each independently from 5 to 10,000.

5. The method of claim 4 , wherein the fluorinated monomer is a fluoromethacrylate monomer.

6. The method of claim 4 , wherein the A block is poly(4-hydroxystyrene), poly(p-chloro styrene), poly(p-bromostyrene), poly(p-iodostyrene), or poly(p-chloromethylstyrene).

7. The method of claim 4 , wherein the B block is a poly(fluromethacrylate) or poly(fluoromethacrylate-co-methacrylate).

8. The method of claim 4 , wherein the B block is poly(2,2,2-trifluoroethylmethacrylate) or poly(2,2,2-trifluoroethyl methacrylate-co-methyl methacrylate).

9. The method of claim 4 , wherein the A block is a styrene block or a hydroxystyrene block, wherein the fluorinated block comprises fluorinated alkyl methacrylate repeat units or a mixture of fluorinated alkyl methacrylate and alkyl methacrylate, and wherein the fluorinated alkyl methacrylate block has from 5 to 1000 fluorinated alkyl methacrylate repeat units and from 0 to 950 alkyl methacrylate repeat units.

10. The method of claim 4 , wherein the A block, B block, or both the A block and B block has one or more crosslinkable moieties.

11. A block copolymer having the following structure:

wherein the A block is a polystyrene block, polyhydroxystyrene block, a substituted analog thereof, or mixture thereof and the B block is a fluorinated block comprising at least one fluorinated monomer, and
wherein x and y are each independently from 5 to 1000.

12. The block copolymer of claim 11 , wherein the block copolymer further comprises one, two, or three additional blocks.

13. The block copolymer of claim 11 , wherein the fluorinated monomer is a fluoromethacrylate monomer.

14. The block copolymer of claim 11 , wherein the A block is a styrene block or a hydroxystyrene block, the fluorinated block comprises fluorinated alkyl methacrylate repeat units or a mixture of fluorinated alkyl methacrylate and alkyl methacrylate, and the fluorinated alkyl methacrylate block has from 5 to 1000 fluorinated alkyl methacrylate repeat units and from 0 to 950 alkyl methacrylate repeat units.

15. The block copolymer of claim 11 , wherein the A block is poly(4-hydroxystyrene), poly(p-chloro styrene), poly(p-bromostyrene), poly(p-iodostyrene), or poly(p-chloromethylstyrene).

16. The block copolymer of claim 11 , wherein the B block is a poly(fluromethacrylate) or poly(fluoromethacrylate-co-methacrylate).

17. The block copolymer of claim 16 , wherein the B block is poly(2,2,2-trifluoroethylmethacrylate) or poly(2,2,2-trifluoroethyl methacrylate-co-methyl methacrylate).

18. The block copolymer of claim 11 , wherein the A block, B block or both the A block and B block has one or more crosslinkable moieties.

19. The block copolymer of claim 11 , wherein the block copolymer is poly(styrene-block-2,2,2-trifluoroethylmethacrylate, poly(t-butoxystyrene-block-2,2,2-trifluoroethylmethacrylate), poly(styrene-block-2,2,2-trifluoroethylmethacrylate-co-methylmethacrylate), or poly(hydroxystyrene-block-2,2,2-trifluoroethylmethacrylate).

20. A thin film comprising the block copolymer of claim 11 .

Assignees

• Ober Christopher K
• Maeda Rina
• You Nam-Ho
• Hayakawa Teruaki
• Univ Cornell

Inventors

• Ober Christopher K
• Maeda Rina
• You Nam-Ho
• Hayakawa Teruaki

Classifications

• G03F7/165

  Monolayers, e.g. Langmuir-Blodgett · CPC title

• G03F7/20

  Exposure; Apparatus therefor (photographic printing apparatus for making copies G03B27/00) · CPC title

• C08F297/026

  polymerising acrylic acid, methacrylic acid or derivatives thereof · CPC title

• G03F7/002

  using materials containing microcapsules; Preparing or processing such materials, e.g. by pressure; Devices or apparatus specially designed therefor · CPC title

• C08F20/22

  Esters containing halogen · CPC title