Resist underlayer film-forming composition, resist underlayer film, and method of producing semiconductor substrate
A resist underlayer film-forming composition includes: a polysiloxane compound including a first structural unit represented by formula (1); and a solvent. X represents a group represented by formula (2); a is an integer of 1 to 3; R 1 represents a halogen atom, a hydroxy group, or a monovalent organic group having 1 to 20 carbon atoms; and b is an integer of 0 to 2; and a sum of a and b is no greater than 3. R 2 represents a monovalent hydrocarbon group having 1 to 20 carbon atoms; n is 1 or 2; R 3 represents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms; L represents a single bond or a divalent linking group; and * denotes a site bonding to the silicon atom in the formula (1). The composition is suitable for lithography with an electron beam or extreme ultraviolet ray.
1 . A resist underlayer film-forming composition comprising:
a polysiloxane compound comprising a first structural unit represented by formula (1); and
a solvent,
wherein,
in the formula (1), X represents a group represented by formula (2); a is an integer of 1 to 3, wherein in a case in which a is no less than 2, a plurality of Xs are identical or different from each other; R 1 represents a halogen atom, a hydroxy group, or a monovalent organic group having 1 to 20 carbon atoms; and b is an integer of 0 to 2, wherein in a case in which b is 2, two R 1 s are identical or different from each other, and wherein a sum of a and b is no greater than 3, and
wherein, in the formula (2), R 2 represents a monovalent hydrocarbon group having 1 to 20 carbon atoms; n is 1 or 2, wherein in a case in which n is 2, a plurality of R 2 s are identical or different from each other; R 3 represents a monovalent organic group having 1 to 20 carbon atoms; L represents a single bond or a divalent linking group; and * denotes a site bonding to the silicon atom in the formula (1),
wherein the resist underlayer film-forming composition is suitable for lithography with an electron beam or extreme ultraviolet ray.
2 . The resist underlayer film-forming composition according to claim 1 , wherein R 2 in the formula (2) represents a monovalent chain hydrocarbon group having 1 to 20 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms.
3 . The resist underlayer film-forming composition according to claim 2 , wherein the monovalent chain hydrocarbon group which is represented by R 2 in the formula (2) has a tertiary carbon atom, and the monovalent chain hydrocarbon group bonds to the oxygen atom at the tertiary carbon atom.
4 . The resist underlayer film-forming composition according to claim 1 , wherein n in the formula (2) is 1.
5 . The resist underlayer film-forming composition according to claim 1 , wherein the monovalent organic group represented by R 3 in the formula (2) is a monovalent hydrocarbon group having 1 to 20 carbon atoms.
6 . The resist underlayer film-forming composition according to claim 1 , wherein the linking group which is represented by L in the formula (2) is a divalent chain hydrocarbon group having 1 to 20 carbon atoms.
7 . The resist underlayer film-forming composition according to claim 1 , wherein the polysiloxane compound further comprises a second structural unit represented by formula (3):
wherein, in the formula (3), R 4 represents a halogen atom, a hydroxy group, or a monovalent organic group having 1 to 20 carbon atoms; c is an integer of 1 to 3, wherein in a case in which c is no less than 2, a plurality of R 4 s are identical or different from each other.
8 . The resist underlayer film-forming composition according to claim 1 , wherein the polysiloxane compound further comprises a third structural unit represented by formula (4):
(SiO 4/2 ) (4)
9 . A resist underlayer film, which is formed from the resist underlayer film-forming composition according to claim 1 .
10 . A method of producing a semiconductor substrate, the method comprising:
applying a resist underlayer film-forming composition directly or indirectly on a substrate to form a coating film;
heating the coating film to form a resist underlayer film;
applying a resist film-forming composition directly or indirectly on the resist underlayer film to form a resist film;
exposing the resist film to an electron beam or extreme ultraviolet ray; and
developing the resist film exposed,
wherein the resist underlayer film-forming composition comprises:
a polysiloxane compound comprising a first structural unit represented by formula (1); and
a solvent,
wherein,
in the formula (1), X represents a group represented by formula (2); a is an integer of 1 to 3, wherein in a case in which a is no less than 2, a plurality of Xs are identical or different from each other; R 1 represents a halogen atom, a hydroxy group, or a monovalent organic group having 1 to 20 carbon atoms; and b is an integer of 0 to 2, wherein in a case in which b is 2, two R 1 s are identical or different from each other, and wherein a sum of a and b is no greater than 3, and
wherein, in the formula (2), R 2 represents a monovalent hydrocarbon group having 1 to 20 carbon atoms; n is 1 or 2, wherein in a case in which n is 2, a plurality of R 2 s are identical or different from each other; R 3 represents a monovalent organic group having 1 to 20 carbon atoms; L represents a single bond or a divalent linking group; and * denotes a site bonding to the silicon atom in the formula (1).
11 . The method according to claim 10 , wherein a heating temperature in the heating of the coating film is no less than 200° C.
12 . The method according to claim 10 , further comprising before the applying of the resist underlayer film-forming composition,
forming an organic underlayer film directly or indirectly on the substrate.
13 . The method according to claim 10 , further comprising removing the resist underlayer film with a removing liquid comprising an acid.