Composition for underlayer film formation, underlayer film for directed self-assembled film and forming method thereof, and directed self-assembly lithography process
A composition includes a polymer and a solvent. The polymer (A) satisfies at least one of the conditions (i) and (ii): (i) having in one terminal part of a main chain a block of a first structural unit that includes an amino group; and (ii) having a sulfur atom bonding to one end of the main chain, wherein a monovalent group that includes an amino group bonds to the sulfur atom.
1. A composition, comprising:
a polymer; and
a solvent,
wherein
the polymer comprises a terminal structure represented by formula (1):
wherein, in the formula (1):
R 1 represents a hydrogen atom, a fluorine atom or a monovalent organic group having 1 to 20 carbon atoms;
R 2 represents a single bond, —O—,—COO—or —CONH—;
A 1 represents a monovalent group comprising an amino group;
X represents a hydrogen atom, —SH or —S—A 11 , wherein A 11 represents a monovalent group comprising an amino group;
n is an integer of no less than 2, being number of structural units each represented by (—CH 2 —C(R 1 )(R 2 -A 1 )-); and
* denotes a bonding site to a moiety other than the terminal structure represented by the formula (1) in the main chain of the polymer, and a proportion of the structural units represented by (—CH 2 —C(R 1 )(R 2 -A 1 )-) with respect to total structural units constituting the polymer is greater than 0% and no greater than 30 mol %.
2. The composition according to claim 1 , wherein A 1 and A 11 in the formula (1) are each represented by formula (A):
wherein in the formula (A),
R 3 represents a single bond or a divalent hydrocarbon group having 1 to 20 carbon atoms, and
R 4 and R 5 each independently represent: a hydrogen atom; a monovalent hydrocarbon group having 1 to 20 carbon atoms; or a group having —O—, —CO—, —NH— or a combination thereof between adjacent carbon atoms of the monovalent hydrocarbon group having 1 to 20 carbon atoms, or
at least two of R 3 , R 4 and R 5 taken together represent a part of: an aliphatic heterocyclic structure having 3 to 20 ring atoms; or an aromatic heterocyclic structure having 5 to 20 ring atoms, together with the nitrogen atom to which the at least two of R 3 , R 4 and R 5 bond.
3. The composition according to claim 1 , wherein
the polymer comprises a structural unit derived from a first monomer and a structural unit derived from a second monomer having higher polarity than the first monomer, and
the structural units are in a random arrangement.
4. The composition according to claim 3 , wherein the first monomer is a vinyl aromatic compound.
5. The composition according to claim 3 , wherein the second monomer is (meth)acrylic acid or a (meth)acrylic acid ester.
6. A composition, comprising:
a polymer; and
a solvent,
wherein the polymer comprises a terminal structure represented by formula (2):
*—S—A 2 (2)
wherein, in the formula (2):
A 2 represents a monovalent group comprising an amino group; and
* denotes a bonding site to an end of the main chain of the polymer.
7. The composition according to claim 6 , wherein A 2 in the formula (2) is represented by formula (A):
wherein in the formula (A),
R 3 represents a single bond or a divalent hydrocarbon group having 1 to 20 carbon atoms, and
R 4 and R 5 each independently represent: a hydrogen atom; a monovalent hydrocarbon group having 1 to 20 carbon atoms; or a group having —O—, —CO—, —NH— or a combination thereof between adjacent carbon atoms of the monovalent hydrocarbon group having 1 to 20 carbon atoms, or
at least two of R 3 , R 4 and R 5 taken together represent a part of: an aliphatic heterocyclic structure having 3 to 20 ring atoms; or an aromatic heterocyclic structure having 5 to 20 ring atoms, together with the nitrogen atom to which the at least two of R 3 , R 4 and R 5 bond.
8. The composition according to claim 6 , wherein
the polymer comprises a structural unit derived from a first monomer and a structural unit derived from a second monomer having higher polarity than the first monomer, and
the structural units are in a random arrangement.
9. The composition according to claim 8 , wherein the first monomer is a vinyl aromatic compound.
10. The composition according to claim 8 , wherein the second monomer is (meth)acrylic acid or a (meth)acrylic acid ester.
11. An underlayer film for a directed self-assembled film in a directed self-assembly lithography process, formed from the composition according to claim 1 .
12. The underlayer film according to claim 11 , wherein a static contact angle of pure water on a surface of the underlayer film is no less than 70° and no greater than 90°.
13. A method of forming an underlayer film for a directed self-assembled film in a directed self-assembly lithography process, the method comprising applying the composition according to claim 1 directly or indirectly on a substrate to provide the underlayer film.
14. A directed self-assembly lithography process comprising:
applying the composition according to claim 1 directly or indirectly on an upper face side of a substrate to provide an underlayer film;
applying a composition capable of forming a directed self-assembled film on the upper face side of the underlayer film to form a coating film;
allowing phase separation of the coating film to form the directed self-assembled film having a plurality of phases;
removing at least a part of the plurality of phases of the directed self-assembled film to form a miniaturized pattern; and
etching the substrate using the miniaturized pattern as a mask.
15. The directed self-assembly lithography process according to claim 14 , further comprising, prior to the applying of the composition capable of forming a directed self-assembled film, forming a prepattern having recessed portions on the upper face side of the underlayer film or the substrate, wherein
in the applying of the composition capable of forming a directed self-assembled film, the recessed portions of the prepattern are filled with the composition capable of forming a directed self-assembled film.
16. An underlayer film for a directed self-assembled film in a directed self-assembly lithography process, formed from the composition according to claim 6 .
17. A method of forming an underlayer film for a directed self-assembled film in a directed self-assembly lithography process, the method comprising applying the composition according to claim 6 directly or indirectly on a substrate to provide the underlayer film.
18. A directed self-assembly lithography process comprising:
applying the composition according to claim 6 directly or indirectly on an upper face side of a substrate to provide an underlayer film;
applying a composition capable of forming a directed self-assembled film on the upper face side of the underlayer film to form a coating film;
allowing phase separation of the coating film to form the directed self-assembled film having a plurality of phases;
removing at least a part of the plurality of phases of the directed self-assembled film to form a miniaturized pattern; and
etching the substrate using the miniaturized pattern as a mask.
19. The directed self-assembly lithography process according to claim 18 , further comprising, prior to the applying of the composition capable of forming a directed self-assembled film, forming a prepattern having recessed portions on the upper face side of the underlayer film or the substrate, wherein
in the applying of the composition capable of forming a directed self-assembled film, the recessed portions of the prepattern are filled with the composition capable of forming a directed self-assembled film.
20. The directed self-assembly lithography process according to claim 18 , which is suitable to form a line-and-space pattern or a hole pattern.