Fluorine-containing polymer, purification method, and radiation-sensitive resin composition

1. A radiation-sensitive resin composition comprising:

a fluorine-containing polymer comprising:

a first repeating unit represented by formula (1); and

a second repeating unit represented by formula (2);

a resin having an acid-unstable group;

a radiation-sensitive acid generator comprising an onium ion, the onium ion comprising:

a cation represented by formula (7-1); and

an anion represented by R 17 C n F 2n SO 3 − , an anion represented by R 17 SO 3 − , or both thereof, wherein R 17 represents a bridge alicyclic hydrocarbon group having no more than 12 carbon atoms and optionally being substituted, and n is an integer of 1 to 10;

a nitrogen-containing compound; and

a solvent,

wherein

R 1 represents a hydrogen atom, a methyl group or a trifluoromethyl group;

A represents a connecting group; and

R 2 represents a linear or branched alkyl group having 1 to 6 carbon atoms or a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, the linear or branched alkyl group and the monovalent alicyclic hydrocarbon group represented by R 2 comprising at least one fluorine atom, or a derivative thereof,

wherein

R 3 represents a hydrogen atom, a methyl group or a trifluoromethyl group; and

R 4 individually represents a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms or a derivative thereof, or a linear or branched alkyl group having 1 to 4 carbon atoms,

wherein

R 14 represents a hydrogen atom, a fluorine atom, a hydroxyl group, a linear or branched alkyl group having 1 to 10 carbon atoms, a linear or branched alkoxyl group having 1 to 10 carbon atoms, or a linear or branched alkoxycarbonyl group having 2 to 11 carbon atoms;

R 15 represents a linear or branched alkyl group having 1 to 10 carbon atoms, or an alkoxyl group;

k is an integer of 0 to 2;

in a case where k is 0, R 16 individually represents a linear or branched alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted phenyl group, or a substituted or unsubstituted naphthyl group, or two R 16 s taken together represent a substituted or unsubstituted divalent group which has 2 to 10 carbon atoms;

in a case where k is 1 or 2, R 16 individually represents a linear or branched alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted phenyl group, or a substituted or unsubstituted naphthyl group; and

r is an integer of 1 to 10.

2. The radiation-sensitive resin composition according to claim 1 , wherein the resin comprises a repeating unit comprising a lactone structure.

3. The radiation-sensitive resin composition according to claim 1 , wherein the acid-unstable group of the resin comprises a monocyclic structure or a polycyclic structure.

4. The radiation-sensitive resin composition according to claim 1 , wherein the anion is represented by R 17 C n F 2n SO 3 − .

5. The radiation-sensitive resin composition according to claim 1 , wherein a content of the fluorine-containing polymer is 0.1% or more by weight based on 100% by weight of the radiation-sensitive resin composition.

6. The radiation-sensitive resin composition according to claim 1 , wherein the fluorine-containing polymer has a weight average molecular weight determined by gel permeation chromatography in a range from 1,000 to 50,000.

7. The radiation-sensitive resin composition according to claim 1 , wherein A represents a single bond, an oxygen atom, a sulfur atom, a carbonyloxy group, an oxycarbonyl group, an amide group, a sulfonylamide group, or a urethane group.

8. The radiation-sensitive resin composition according to claim 1 , wherein the nitrogen-containing compound includes at least one of an amine compound, an amide group-containing compound, a urea compound, or a nitrogen-containing heterocyclic compound.

9. The radiation-sensitive resin composition according to claim 1 , wherein a content of the fluorine-containing polymer in the radiation-sensitive resin composition is from 0.5% to 30% by weight based on 100% by weight of the radiation-sensitive resin composition.

10. The radiation-sensitive resin composition according to claim 1 , wherein an amount of the radiation-sensitive acid generator is from 0.5 to 10 parts by weight based on 100 parts by weight of a total of the fluorine-containing polymer and the resin.

11. The radiation-sensitive resin composition according to claim 1 , wherein R 16 individually represents a substituted or unsubstituted phenyl group or a substituted or unsubstituted naphthyl group.