Directed self-assembling composition for pattern formation, and pattern-forming method

1. A directed self-assembling composition comprising:

a block copolymer comprising:

a polystyrene block having a styrene unit; and

a polyalkyl (meth)acrylate block having an alkyl (meth)acrylate unit; and

a solvent in which phase separation of the block copolymer occurs,

the block copolymer comprising an organic group that is bound to at least one end of a main chain of the polyalkyl (meth)acrylate block and that comprises a hetero atom,

wherein a polymerization initiation end of the block copolymer comprises a structure derived from an alkyl lithium,

wherein the organic group included in the block copolymer comprises a nitrogen atom, a sulfur atom, a phosphorus atom, a tin atom, or a combination thereof, or is represented by formula (1):

wherein, in the formula (1), R 1 represents a single bond or a divalent organic group having 1 to 30 carbon atoms; and R 2 represents a hydrogen atom, an aliphatic linear hydrocarbon group having 1 to 30 carbon atoms, an alicyclic hydrocarbon group having 3 to 30 carbon atoms, or a group in which the aliphatic linear hydrocarbon group having 1 to 30 carbon atoms or the alicyclic hydrocarbon group having 3 to 30 carbon atoms comprises a hetero atom between adjacent two carbon atoms, and

wherein the block copolymer is a diblock copolymer and the organic group is not a monomeric unit included in the block copolymer.

2. The directed self-assembling composition according to claim 1 , wherein the alkyl (meth)acrylate unit is a methyl methacrylate unit.

3. The directed self-assembling composition according to claim 1 , wherein a molar ratio of styrene units to alkyl (meth)acrylate units in the block copolymer is no less than 10/90 and no greater than 90/10.

4. The directed self-assembling composition according to claim 1 , wherein the organic group included in the block copolymer is derived from an epoxy compound.

5. A pattern-forming method comprising:

applying the directed self-assembling composition according to claim 1 on a substrate to provide a directed self-assembling film having a phase separation structure on the substrate; and

removing a part of phases of the directed self-assembling film.

6. The pattern-forming method according to claim 5 ,

wherein the method further comprises before providing the directed self-assembling film:

providing an underlayer film on the substrate; and

forming a prepattern on the underlayer film,

wherein the directed self-assembling film is provided in a region compartmentalized by the prepattern on the underlayer film, and

wherein the method further comprises after providing the directed self-assembling film,

removing the prepattern.

7. The pattern-forming method according to claim 5 , wherein the pattern obtained is a line-and-space pattern or a hole pattern.

8. The directed self-assembling composition according to claim 1 , wherein the hetero atom is a nitrogen atom, a sulfur atom, a phosphorus atom, a tin atom or a combination thereof.

9. The directed self-assembling composition according to claim 1 , wherein R 1 represents a divalent organic group having 2 to 30 carbon atoms.

10. The directed self-assembling composition according to claim 1 , wherein R 1 represents an aliphatic linear hydrocarbon group having 2 to 30 carbon atoms and optionally comprising a hetero atom between adjacent two carbon atoms, an alicyclic hydrocarbon group having 3 to 30 carbon atoms and optionally comprising a hetero atom between adjacent two carbon atoms, or an aromatic hydrocarbon group having 6 to 30 carbon atoms and optionally comprising a hetero atom between adjacent two carbon atoms.

11. The directed self-assembling composition according to claim 1 , wherein the organic group included in the block copolymer is represented by the formula (1).

12. The directed self-assembling composition according to claim 11 , wherein R 1 represents a divalent organic group having 2 to 30 carbon atoms.

13. The directed self-assembling composition according to claim 11 , wherein R 1 represents an aliphatic linear hydrocarbon group having 2 to 30 carbon atoms and optionally comprising a hetero atom between adjacent two carbon atoms, an alicyclic hydrocarbon group having 3 to 30 carbon atoms and optionally comprising a hetero atom between adjacent two carbon atoms, or an aromatic hydrocarbon group having 6 to 30 carbon atoms and optionally comprising a hetero atom between adjacent two carbon atoms.

14. The pattern-forming method according to claim 5 , wherein the organic group included in the block copolymer is represented by the formula (1).

15. The pattern-forming method according to claim 14 , wherein R 1 represents a divalent organic group having 2 to 30 carbon atoms.

16. The pattern-forming method according to claim 14 , wherein R 1 represents an aliphatic linear hydrocarbon group having 2 to 30 carbon atoms and optionally comprising a hetero atom between adjacent two carbon atoms, an alicyclic hydrocarbon group having 3 to 30 carbon atoms and optionally comprising a hetero atom between adjacent two carbon atoms, or an aromatic hydrocarbon group having 6 to 30 carbon atoms and optionally comprising a hetero atom between adjacent two carbon atoms.