Method for forming pattern, and composition for forming resist underlayer film
A method for forming a pattern includes providing a resist underlayer film on a substrate using a first composition for forming a resist underlayer film. The first composition includes a polymer having a structural unit represented by a following formula (1). In the formula (1), Ar 1 and Ar 2 each independently represent a bivalent group represented by a following formula (2). A resist coating film is provided on the resist underlayer film using a resist composition. A resist pattern is formed using the resist coating film. A predetermined pattern is formed on the substrate by sequentially dry-etching the resist underlayer film and the substrate using the resist pattern as a mask.
1. A method for forming a pattern, comprising:
providing a resist underlayer film on a substrate using a first composition for forming a resist underlayer film, the first composition comprising:
a polymer comprising a structural unit represented by formula (1):
wherein, in the formula (1), Ar 1 and Ar 2 each independently represent a bivalent group represented by formula (2):
wherein, in the formula (2), R 1 and R 2 each independently represent a bivalent aromatic group; R 3 represents a single bond, —O—, —CO—, —SO— or —SO 2 —; and a is an integer of 0 to 3, wherein in a case where “a” is 2 or more, each of a plurality of R 2 s and a plurality of R 3 are a same or different;
providing a resist coating film on the resist underlayer film using a resist composition;
forming a resist pattern using the resist coating film; and
forming a predetermined pattern on the substrate by sequentially dry-etching the resist underlayer film and the substrate using the resist pattern as a mask.
2. The method according to claim 1 , wherein R 1 and R 2 in the formula (2) are each independently represented by formula (3):
wherein, in the formula (3),
R 4 represents a halogen atom, a hydroxy group, a cyano group, a nitro group, a monovalent hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms or a hydroxyalkyl group having 1 to 20 carbon atoms;
b is an integer of 0 to 6, wherein in a case where b is 2 or greater, a plurality of R 4 s are a same or different; and
c is 0 or 1.
3. The method according to claim 1 , wherein a weight average molecular weight in terms of a polystyrene equivalent of the polymer is no less than 500 and no greater than 10,000.
4. The method according to claim 1 , wherein the first composition further comprises a solvent.
5. The method according to claim 1 , wherein the first composition further comprises an acid generating agent.
6. The method according to claim 1 , wherein the first composition further comprises a crosslinking agent.
7. The method according to claim 1 , wherein the step of forming the resist pattern comprises:
exposing the resist coating film by selective irradiation with the radioactive ray; and
developing the exposed resist coating film.
8. A composition for forming a resist underlayer film, comprising:
a polymer comprising a structural unit represented by formula (1):
wherein, in the formula (1), Ar l and Ar 2 each independently represent a bivalent group represented by the formula (2):
wherein, in the formula (2), R 1 and R 2 each independently represent a bivalent aromatic group; R 3 represents a single bond, —O—, —CO—, —SO— or —SO 2 ; and a is an integer of 0 to 3, wherein in a case where “a” is 2 or more, each of a plurality of R 2 s and a plurality of R 3 s are a same or different.
9. The composition for forming a resist underlayer film according to claim 8 , wherein R 1 and R 2 in the formula (2) are each independently represented by formula (3):
wherein, in the formula (3),
R 4 represents a halogen atom, a hydroxy group, a cyano group, a nitro group, a monovalent hydrocarbon group having 1 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms or a hydroxyalkyl group having 1 to 20 carbon atoms;
b is an integer of 0 to 6, wherein in a case where b is 2 or greater, a plurality of R 4 s are a same or different; and
c is 0 or 1.
10. The composition for forming a resist underlayer film according to claim 8 , wherein a weight average molecular weight in terms of a polystyrene equivalent of the polymer is no less than 500 and no greater than 10,000.
11. The method according to claim 1 , wherein an amount of the structural unit contained in the polymer is no less than 50 mol % with respect to a total of the structural units constituting the polymer.
12. The method according to claim 1 , wherein an amount of the structural unit contained in the polymer is no less than 80 mol % with respect to a total of the structural units constituting the polymer.
13. The composition for forming a resist underlayer film according to claim 8 , wherein an amount of the structural unit contained in the polymer is no less than 50 mol % with respect to a total of the structural units constituting the polymer.
14. The composition for forming a resist underlayer film according to claim 8 , wherein an amount of the structural unit contained in the polymer is no less than 80 mol % with respect to a total of the structural units constituting the polymer.