RADIATION-SENSITIVE RESIN COMPOSITION AND METHOD OF FORMING RESIST PATTERN

1 . A radiation-sensitive resin composition comprising:

a first polymer comprising a first structural unit comprising a partial structure obtained by substituting a hydrogen atom of a carboxy group or of a phenolic hydroxy group with an acid-labile group represented by formula (1); and

a compound comprising: a monovalent radiation-sensitive onium cation moiety comprising an aromatic ring structure which comprises a fluorine atom or a fluorine atom-containing group; and a monovalent organic acid anion moiety,

wherein, in the formula (1),

Ar 1 represents a group obtained by removing one hydrogen atom from a substituted or unsubstituted aromatic ring structure having 5 to 30 ring atoms;

R 1 and R 2 each independently represent a substituted or unsubstituted monovalent aliphatic hydrocarbon group having 1 to 10 carbon atoms; and

* denotes a site bonding to an ethereal oxygen atom in the carboxy group or an oxygen atom in the phenolic hydroxy group.

2 . The radiation-sensitive resin composition according to claim 1 , wherein the substituted or unsubstituted aromatic ring structure having 5 to 30 ring atoms which gives Ar 1 in the formula (1) is a substituted or unsubstituted aromatic hydrocarbon ring structure having 6 to 30 ring atoms.

3 . The radiation-sensitive resin composition according to claim 1 , wherein R 1 and R 2 in the formula (1) each independently represent a substituted or unsubstituted monovalent chain hydrocarbon group having 1 to 10 carbon atoms.

4 . The radiation-sensitive resin composition according to claim 1 , wherein the radiation-sensitive onium cation moiety is represented by formula (2-1) or (2-2):

wherein,

in the formula (2-1),

a is an integer of 0 to 7, b is an integer of 0 to 4, and c is an integer of 0 to 4, wherein a sum of a, b, and c is no less than 1;

R 3 , R 4 , and R 5 each independently represent a halogen atom, a hydroxy group, a nitro group, or a monovalent organic group having 1 to 20 carbon atoms, wherein at least one of R 3 , R 4 , and R 5 represents a fluorine atom or a monovalent fluorinated hydrocarbon group having 1 to 10 carbon atoms;

in a case in which a is no less than 2, a plurality of R 3 s are identical or different from each other, in a case in which b is no less than 2, a plurality of R 4 s are identical or different from each other, and in a case in which c is no less than 2, a plurality of R 5 s are identical or different from each other;

R 6 and R 7 each independently represent a hydrogen atom, a fluorine atom, or a monovalent fluorinated hydrocarbon group having 1 to 10 carbon atoms, or R 6 and R 7 taken together represent a single bond; and

n 1 is 0 or 1, and

in the formula (2-2),

d is an integer of 1 to 7 and e is an integer of 0 to 10, wherein in a case in which d is 1, R 8 represents a fluorine atom or a monovalent fluorinated hydrocarbon group having 1 to 10 carbon atoms, and in a case in which d is no less than 2, a plurality of R 8 s are identical or different from each other, and each R 8 represents a halogen atom, a hydroxy group, a nitro group, or a monovalent organic group having 1 to 20 carbon atoms, wherein at least one of the plurality of R 8 s represents a fluorine atom or a monovalent fluorinated hydrocarbon group having 1 to 10 carbon atoms;

R 9 represents a single bond or a divalent organic group having 1 to 20 carbon atoms;

R 10 represents a halogen atom, a hydroxy group, a nitro group, or a monovalent organic group having 1 to 20 carbon atoms, wherein in a case in which e is no less than 2, a plurality of R 10 s are identical or different from each other;

n 2 is 0 or 1; and

n 3 is an integer of 0 to 3.

5 . The radiation-sensitive resin composition according to claim 1 , wherein the first structural unit is represented by formula (3-1) or (3-2):

wherein,

in the formulae (3-1) and (3-2), Z represents the acid-labile group represented by the formula (1);

in the formula (3-1), R 11 represents a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group; and

in the formula (3-2),

R 12 represents a hydrogen atom or a methyl group;

R 13 represents a single bond, an oxygen atom, —COO—, or —CONH—;

Ar 2 represents a group obtained by removing two hydrogen atoms from a substituted or unsubstituted aromatic hydrocarbon ring structure having 6 to 30 ring atoms; and

R 14 represents a single bond or —CO—.

6 . The radiation-sensitive resin composition according to claim 1 , wherein the first polymer further comprises a second structural unit comprising a phenolic hydroxy group.

7 . The radiation-sensitive resin composition according to claim 1 , further comprising a second polymer having a percentage content of fluorine atoms which is greater than a percentage content of fluorine atoms of the first polymer.

8 . A method of forming a resist pattern, the method comprising:

applying the radiation-sensitive resin composition according to claim 1 directly or indirectly on a substrate to form a resist film;

exposing the resist film; and

developing the resist film exposed.