Composition for pattern formation, pattern-forming method, and block copolymer

1. A composition for pattern formation comprising:

a block copolymer that forms a phase separation structure by directed self-assembly; and

a solvent,

wherein the block copolymer comprises a first block composed of a first repeating unit that comprises a silicon atom, a second block composed of a second repeating unit that does not include a silicon atom, and a first group that bonds to at least one end of a main chain and links to the first block,

wherein the first group is a monovalent group that forms a compound having ClogP of no less than 2.4 provided that a methyl group is bonded to an atom on a side of the main chain, and

wherein the first group does not comprise a hetero atom.

2. The composition for pattern formation according to claim 1 , wherein the first group is a monovalent hydrocarbon group having 3 to 25 carbon atoms.

3. The composition for pattern formation according to claim 1 , wherein the first group is an alkyl group, a cycloalkyl group, an aryl group, or an aralkyl group.

4. The composition for pattern formation according to claim 1 , wherein the first repeating unit is represented by the following formula (1):

wherein, in the formula (1),

R 1 represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group;

R 2 represents a single bond, —O—, —COO— or —CONH—; and

R a represents a monovalent group having 1 to 20 silicon atoms.

5. The composition for pattern formation according to claim 1 , wherein the second repeating unit is a (meth)acrylic acid ester unit, or a substituted or unsubstituted styrene unit.

6. The composition for pattern formation according to claim 1 , wherein the block copolymer is a diblock copolymer or a triblock copolymer.

7. The composition for pattern formation according to claim 1 , wherein the number of carbon atoms of the first group is at least 6.

8. A pattern-forming method comprising:

forming on one face side of a substrate, a directed self-assembling film in which phase separation is caused; and

removing a part of the directed self-assembling film,

wherein the directed self-assembling film is formed from a composition,

wherein the composition comprises:

a block copolymer that forms a phase separation structure by directed self-assembly; and

a solvent,

wherein the block copolymer comprises a first block composed of a first repeating unit that comprises a silicon atom, a second block composed of a second repeating unit that does not include a silicon atom, and a first group that bonds to at least one end of a main chain and links to the first block,

wherein the first group is a monovalent group that forms a compound having ClogP of no less than 2.4 provided that a methyl group is bonded to an atom on a side of the main chain, and

wherein the first group does not comprise a hetero atom.

9. The pattern-forming method according to claim 8 , further comprising before the forming the directed self-assembling film, forming an underlayer film on one face side of the substrate,

wherein in the forming the directed self-assembling film, the directed self-assembling film is formed on a side of the underlayer film not facing the substrate.

10. The pattern-forming method according to claim 8 , further comprising before the forming the directed self-assembling film,

forming a prepattern on one face side of the substrate,

wherein in the forming the directed self-assembling film, the directed self-assembling film is formed in a region where the prepattern is not provided.

11. The pattern-forming method according to claim 8 , wherein a line-and-space pattern or a hole pattern is formed.

12. The pattern-forming method according to claim 8 , wherein the first group is a monovalent chain hydrocarbon group having 3 to 25 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 25 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 25 carbon atoms.

13. The pattern-forming method according to claim 8 , wherein the first group is a monovalent hydrocarbon group having 3 to 25 carbon atoms.

14. The pattern-forming method according to claim 8 , wherein the first group is an alkyl group, a cycloalkyl group, an aryl group, or an aralkyl group.

15. The pattern-forming method according to claim 8 , wherein the first repeating unit is represented by the following formula (1):

wherein, in the formula (1),

R 1 represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group;

R 2 represents a single bond, —O—, —COO— or —CONH—; and

R a represents a monovalent group having 1 to 20 silicon atoms.

16. The pattern-forming method according to claim 8 , wherein the second repeating unit is a (meth)acrylic acid ester unit, or a substituted or unsubstituted styrene unit.

17. The pattern-forming method according to claim 8 , wherein the block copolymer is a diblock copolymer or a triblock copolymer.

18. The pattern-forming method according to claim 8 , wherein the first group is a monovalent group that forms a compound having ClogP of no less than 5.5 provided that a methyl group is bonded to an atom on the side of the main chain.

19. The pattern-forming method according to claim 8 , wherein the first group is a monovalent group that forms a compound having ClogP of no greater than 7 provided that a methyl group is bonded to an atom on the side of the main chain.

20. A block copolymer that forms a phase separation structure by directed self-assembly, comprising:

a first block composed of a first repeating unit that includes a silicon atom; a second block composed of a second repeating unit that does not include a silicon atom; and a first group that bonds to at least one end of a main chain and links to the first block,

wherein the first group is a monovalent group that forms a compound having ClogP of no less than 2.4 provided that a methyl group is bonded to an atom on a side of the main chain, and

wherein the first group does not comprise a hetero group.