Radiation-sensitive resin composition, method for forming resist pattern, polymer and polymerizable compound

1. A radiation-sensitive resin composition comprising:

a first polymer including an acid-labile group;

an acid generator to generate an acid upon exposure to radiation; and

a second polymer including a fluorine atom and a repeating unit shown by a general formula (c1), the second polymer having a fluorine atom content higher than a fluorine atom content of the first polymer,

wherein

n is an integer from 1 to 3,

R 1 represents an alkali-labile group, wherein each R 1 is a same as or different form each other when n is 2 or 3,

A represents an oxygen atom or —CO—O— # , wherein the oxygen atom represented by A is not bonded directly to an aromatic ring, a carbonyl group which is not included in R 1 , or a sulfoxyl group, “#” indicates a bonding hand bonded to R 1 , and each A is a same as or different form each other when n is 2 or 3,

R 2 represents a single bond, a divalent chain hydrocarbon group having 1 to 10 carbon atoms, or a divalent cyclic hydrocarbon group having 4 to 20 carbon atoms, wherein each R 2 is a same as or different form each other when n is 2 or 3,

X 1 represents a single bond, a difluoromethylene group, or a linear or branched perfluoroalkylene group having 2 to 20 carbon atoms, wherein each X 1 is a same as or different form each other when n is 2 or 3,

R 3 represents an (n+1)-valent hydrocarbon group having 1 to 20 carbon atoms, wherein, optionally, an oxygen atom, a sulfur atom, an imino group, a carbonyl group, —CO—O—, or —CO—NH— is bonded to an end of R 3 which is bonded to R 2 ,

E represents an oxygen atom, —CO—O— ### , or —CO—NH— #### , wherein “###” and “####” indicates a bonding hand bonded to R 3 ,

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

in a case where A represents —CO—O— # , R 1 bonded to the —CO—O— # group represents a group shown by a general formula (1), a general formula (2) or a general formula (3),

wherein R 10 represents a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an acyl group having 1 to 10 carbon atoms, or an acyloxy group having 1 to 10 carbon atoms, whrein each R 10 is either a same as or different from each other when a plurality of R 10 are present,

m 1 is an integer from 0 to 5,

m 2 is an integer from 0 to 4, and

each of R 11 and R 12 independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, or R 11 and R 12 bond to each other to form an alicyclic hydrocarbon group having 4 to 20 carbon atoms together with the carbon atom bonded to R 11 and R 12 ,

wherein the second polymer further includes a repeating unit shown by a general formula (c3) or a repeating unit shown by a general formula (c4),

wherein

R is a same as defined for the general formula (c1),

G represents a single bond, an oxygen atom, a sulfur atom, —CO—O—, —SO 2 —O—NH—, —CO—NH—, or —O—CO—NH—, and

R 4 represents a fluorine-substituted chain hydrocarbon group having 1 to 6 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom, or a fluorine-substituted cyclic hydrocarbon group having 4 to 20 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom, and

wherein

m is an integer from 1 to 3,

R is a same as defined for the general formula (c1), wherein each R is either a same as or different from each other when m is 2 or 3,

A is a same as defined for the general formula (c1), wherein each A is either a same as or different from each other when m is 2 or 3,

R 7 represents a hydrogen atom or an acid-labile group, wherein each R 7 is either a same as or different from each other when m is 2 or 3,

R 6 is a same as defined for R 2 in the general formula (c1), wherein each R 6 is either a same as or different from each other when m is 2 or 3,

R 5 is a same as defined for R 3 in the general formula (c1), and

X 2 is a same as defined for X 1 in the general formula (c1), wherein each X 2 is either a same as or different from each other when m is 2 or 3.

2. The radiation-sensitive resin composition according to claim 1 , wherein the second polymer includes a repeating unit shown by a general formula (c2),

wherein each of n, R, R 1 , R 2 , R 3 , X 1 , and A is a same as defined for the general formula (c1).

3. The radiation-sensitive resin composition according to claim 1 , wherein the second polymer includes a repeating unit shown by a general formula (c2-1),

wherein each of n, R, R 2 , R 3 , and X 1 is a same as defined for the general formula (c1),

R 8 represents a fluorine-substituted hydrocarbon group having 1 to 10 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom, and

R 8 and the CO group bonded to R 8 taken together are an alkali-labile group.

4. The radiation-sensitive resin composition according to claim 1 , wherein the second polymer includes a repeating unit shown by a general formula (c2-2),

wherein

each of R, R 2 , and X 1 is a same as defined for the general formula (c1),

R 31 represents a divalent chain hydrocarbon group having 1 to 10 carbon atoms or a divalent cyclic hydrocarbon group having 4 to 20 carbon atoms, wherein, optionally, an oxygen atom, a sulfur atom, an imino group, a carbonyl group, —CO—O—, or —CO—NH— is bonded to an end of R 31 which is bonded to R 2 , and

R 9 is an alkali-labile group and represents a group shown by a general formula (1), a general formula (2) or a general formula (3),

wherein R 10 represents a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an acyl group having 1 to 10 carbon atoms, or an acyloxy group having 1 to 10 carbon atoms, whrein each R 10 is either a same as or different from each other when a plurality of R 10 are present,

m 1 is an integer from 0 to 5,

m 2 is an integer from 0 to 4, and

each of R 11 and R 12 independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, or R 11 and R 12 bond to each other to form an alicyclic hydrocarbon group having 4 to 20 carbon atoms together with the carbon atom bonded to R 11 and R 12 .

5. The radiation-sensitive resin composition according to claim 1 , including the second polymer in an amount of 0.1 to 20 parts by mass based on 100 parts by mass of the first polymer.

6. A method for forming a resist pattern comprising:

forming a resist film on a substrate using the radiation-sensitive resin composition according to claim 1 ;

exposing the resist film by applying radiation to the resist film via a mask pattern; and

developing the exposed resist film to form a resist pattern.

7. The method according to claim 6 , wherein the resin film is exposed via an immersion liquid provided over the resist film.