Methods of forming block copolymers, and block copolymer compositions

• US 8,450,418 B2
• Filed: 09/14/2012
• Issued: 05/28/2013
• Est. Priority Date: 08/20/2010
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Millward, Dan B., Sills, Scott E.
• Primary Examiner(s): Loewe, Robert S
• Application Number:
  US13/618,480
• Publication Number:
  US 20130017335A1
• Time in Patent Office: 256 Days
• Field of Search: None
• US Class Current: 525/105
• CPC Class Codes: C08F 226/06 by a heterocyclic ring containing nitrogen
• CPC Class Codes: C08F 287/00 Macromolecular compounds obtained by polymerising monomers on to block polymers
• CPC Class Codes: C08F 293/00 Macromolecular compounds obtained by polymerisation on to a macromolecule having groups capable of inducing the formation of new polymer chains bound exclusively at one or both ends of the starting macromolecule on to polymers modified by introduction of unsaturated end groups C08F290/02
• CPC Class Codes: C08F 8/00 Chemical modification by after-treatment graft polymers, block polymers, crosslinking with unsaturated monomers or with polymers C08F251/00 - C08F299/00; of conjugated diene rubbers C08C
• CPC Class Codes: C08F 8/42 Introducing metal atoms or metal-containing groups
• CPC Class Codes: G03F 7/0002 Lithographic processes using patterning methods other than those involving the exposure to radiation, e.g. by stamping

Abstract

Methods of modifying block copolymers to enhance thermodynamic properties thereof without sacrificing material properties and methods of forming modified block copolymers having desired properties are disclosed. The modified block copolymers may be used, for example, as a mask for sublithographic patterning during various stages of semiconductor device fabrication. For example, block copolymers having desirable material properties, such as etch selectively, may be chemically modified to tailor a χ value thereof to optimize the process conditions for achieving a self-assembled state and to reduce a defectivity of the self-assembled block copolymer pattern.

Claims

1. A method of forming a block copolymer, comprising grafting at least one modifying polymer segment onto at least one of a plurality of polymer blocks of a block copolymer to form a modified block copolymer having an χ

N value between about 40 and about 135.

2. The method of claim 1, further comprising grafting at least one additional modifying polymer segment onto the modified block copolymer.

3. The method of claim 1, wherein grafting at least one modifying polymer segment onto at least one of the plurality of polymer blocks comprises grafting the at least one modifying polymer segment onto a polystyrene-b-polydimethylsiloxane block copolymer.

4. The method of claim 3, wherein grafting the at least one modifying polymer segment onto a polystyrene-b-polydimethylsiloxane block copolymer comprises grafting a polydimethylsiloxane block to at least one polystyrene block of the polystyrene-b-polydimethylsiloxane block copolymer.

5. The method of claim 3, wherein grafting the at least one modifying polymer segment onto a polystyrene-b-polydimethylsiloxane block copolymer comprises peroxide-cure grafting a vinyl(dimethyl)siloxy ether of a hydroxy-terminated polystyrene block to at least one polydimethylsiloxane block of the polystyrene-b-polydimethylsiloxane block copolymer.

6. The method of claim 1, wherein grafting the at least one modifying polymer segment onto at least one of a plurality of polymer blocks of a block copolymer comprises grafting the at least one modifying polymer segment to a polystyrene-b-poly(4-vinylpyridine) block copolymer.

7. The method of claim 6, wherein grafting the at least one modifying polymer segment onto a polystyrene-b-poly(4-vinylpyridine) block copolymer comprises grafting at least one polystyrene propynoate segment to a 4-(azidomethyl)styrene within at least one polystyrene block of the polystyrene-b-poly(4-vinylpyridine) block copolymer.

8. The method of claim 6, wherein grafting the at least one modifying polymer segment onto a polystyrene-b-poly(4-vinylpyridine) block copolymer comprises grafting a hydroxy-terminated poly(4-vinylpyridine) oligomer segment to a 4-(bromomethyl)styrene segment within at least one polystyrene block of the polystyrene-b-poly(4-vinylpyridine) block copolymer.

9. The method of claim 1, wherein grafting at least one modifying polymer segment onto at least one of a plurality of polymer blocks of a block copolymer comprises randomly distributing a plurality of modifying polymer segments onto the at least one of the plurality of polymer blocks.

10. A method of forming a self-assembled block copolymer structure, comprising:

modifying at least one of a plurality of polymer blocks of a block copolymer to modify an χ

value between at least two of the plurality of polymer blocks and form a modified block copolymer having an χ

N value between about 40 and about 135;

applying the modified block copolymer over a substrate; and

annealing the modified block copolymer to form a plurality of ordered domains;

wherein modifying at least one of a plurality of polymer blocks of a block copolymer to modify an χ

value between at least two of the plurality of polymer blocks comprises chemically modifying a polystyrene block of at least one of a polystyrene-b-polydimethylsiloxane block copolymer and a polystyrene-b-poly(4-vinylpyridine) block copolymer.

11. A block copolymer composition, comprising:

a modified block copolymer having an χ

N value between about 40 and about 135 and comprising;

a first polymer block comprising;

a plurality of styrene monomers; and

a plurality of modifying monomers; and

a second polymer block covalently linked to the first polymer block and comprising a plurality of monomers selected from the group consisting of dimethylsiloxane monomers and 4-vinylpyridine monomers.

12. The block copolymer composition of claim 11, wherein the plurality of modifying monomers comprises at least one of a plurality of siloxystyrene monomers, a plurality of hydroxystyrene monomers, and a plurality of silyl ether monomers.

13. The block copolymer composition of claim 11, wherein the plurality of modifying monomers comprises at least one of a plurality of 4-trimethylsiloxystyrene monomers, a plurality of hydroxystyrene monomers, and a plurality of trimethylsilyl ether monomers.

14. The block copolymer composition of claim 11, wherein the plurality of modifying monomers are randomly distributed in the plurality of styrene monomers.

15. The block copolymer composition of claim 11, wherein the plurality of styrene monomers alternate with the plurality of modifying monomers.

16. The block copolymer composition of claim 11, wherein the first polymer block further comprises at least one polymer segment grafted to at least one of the plurality of modifying monomers.

17. The block copolymer composition of claim 11, wherein the second polymer block further comprises another plurality of modifying monomers.

18. The block copolymer composition of claim 17, wherein the another plurality of modifying monomers are randomly distributed in the plurality of monomers.

19. The block copolymer composition of claim 17, wherein the plurality of modifying monomers alternate with the another plurality of modifying monomers.