Resist composition and patterning process

1. A resist composition comprising:

a polymer compound having

one or two repeating units selected from repeating units represented by the following general formulae (p-1), (p-2) and (p-3),

a repeating unit represented by the following formula (a-1) and a repeating unit represented by the following formula (a-2) the polarities of which are changed by an action of an acid, and

a repeating unit represented by the following formula (b-1);

a salt represented by the following general formula (B); and

a solvent,

wherein a difference between a C log P of the repeating unit (a-1) and a C log P of the repeating unit (a-1) after changing the polarity thereof by an action of an acid is 3.3 to 4.2, and a difference between a C log P of the repeating unit (a-2) and a C log P of the repeating unit (a-2) after changing the polarity thereof by an action of an acid is 2.5 to 3.2:

in the above-mentioned formulae (p-1), (p-2) and (p-3),

R 1 , R 4 and R 6 are each independently a hydrogen atom or a methyl group;

Z 1 is a single bond, a phenylene group, —O—Z 11 —, —C(═O)—O—Z 11 — or —C(═O)—NH—Z 11 —;

Z 11 is an alkanediyl group having 1 to 6 carbon atoms or an alkenediyl group having 2 to 6 carbon atoms, or a phenylene group, each of which may contain a carbonyl group, an ester bond, an ether bond or a hydroxyl group;

Z 2 is a single bond, —Z 21 —C(O)—O—, —Z 21 —O— or —Z 21 —O—C(═O)—, Z 21 is an alkanediyl group having 1 to 12 carbon atoms, and may contain a carbonyl group, an ester bond or an ether bond;

R 2 to R 3 are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom(s);

R 5 is a hydrogen atom or a trifluoromethyl group;

Z 3 is a single bond, a methylene group, an ethylene group, a phenylene group, a fluorinated phenylene group, —O—Z 31 —, —C(═O)—O—Z 31 — or —C(═O)—NH—Z 31 —, Z 31 is an alkylene group having 1 to 6 carbon atoms, a phenylene group, a fluorinated phenylene group, a phenylene group substituted with a trifluoromethyl group, or a linear, branched or cyclic alkenylene group having 2 to 6 carbon atoms, each of which may contain a carbonyl group, an ester bond, an ether bond or a hydroxyl group;

M 1+ represents a counter cation having a substituent(s), and represents a sulfonium cation, an iodonium cation or an ammonium cation;

M 0− is a non-nucleophilic counter ion;

in the above-mentioned formula (a-1),

R 7 is a hydrogen atom or a methyl group;

Y has a structure that changes its polarity by an action of an acid and becomes soluble in an aqueous alkali solution;

in the above-mentioned formula (a-2),

R 8 is a hydrogen atom or a methyl group;

Z 4 is a single bond, a methylene group, an ethylene group, a phenylene group, a fluorinated phenylene group, —O—Z 41 —, —C(═O)—O—Z 41 — or —C(═O)—NH—Z 41 —, Z 41 is an alkanediyl group having 1 to 12 carbon atoms, and may contain a carbonyl group, an ester bond or an ether bond;

R 9 to R 11 each independently represent a hydrocarbon group which is linear having 1 to 10 carbon atoms, or branched or cyclic having 3 to 10 carbon atoms, and two of which may be bonded to each other to form a ring;

in the above-mentioned formula (b-1),

R 12 is a hydrogen atom or a methyl group;

Z 5 is a single bond, a methylene group, an ethylene group, a phenylene group, a fluorinated phenylene group, —O—Z 51 —, —C(═O)—O—Z 51 — or —C(═O)—NH—Z 51 —, Z 51 is an alkanediyl group having 1 to 12 carbon atoms, and may contain a carbonyl group, an ester bond or an ether bond;

n1 is an integer of 1 to 3, n2 is an integer of 0 to 3 and a sum of n1 and n2 is 5 or less;

R 13 is a fluorine atom, an iodine atom, or a hydrocarbon group which is linear having 1 to 10 carbon atoms, or branched or cyclic having 3 to 10 carbon atoms, —CH 2 — constituting the hydrocarbon group may be replaced by —O—, —C(═O)—O— or —C(═O)—, or a hydrogen atom constituting the hydrocarbon group may be substituted with a halogen atom or a hetero atom;

Ma-CO 2 − M 2+    (B)

in the formula (B),

Ma represents a linear, branched or cyclic monovalent hydrocarbon group having 1 to 35 carbon atoms which may contain an oxygen atom(s), and one or more hydrogen atoms bonded to the carbon atom may be substituted with a fluorine atom(s); and

M 2+ represents a counter cation having a substituent(s), and is a sulfonium cation, an iodonium cation or an ammonium cation.

2. The resist composition according to claim 1 , wherein the polymer compound further contains a repeating unit having a lactone structure represented by the following general formula (c-1):

in the formula (c-1),

R 14 is a hydrogen atom or a methyl group;

X 1 is a single bond or a hydrocarbon group having 1 to 5 carbon atoms and —CH 2 — constituting the hydrocarbon group may be replaced by —O—, —C(═O)—O— or —C(═O)—; and

L is a group having a lactone structure.

3. The resist composition according to claim 2 , wherein L in the formula (c-1) is a group represented by any of the following formulae (c-1-1), (c-1-2) and (c-1-3):

in the formula (c-1-1),

n3 is an integer of 1 to 4;

R 15 is a hydrocarbon group which is linear having 1 to 10 carbon atoms, or branched or cyclic having 3 to 10 carbon atoms, —CH 2 — constituting the hydrocarbon group may be replaced by —O—, —C(═O)—O— or —C(═O)—, or a hydrogen atom constituting the hydrocarbon group may be substituted with a halogen atom or a hetero atom;

n4 represents a linking group having 1 to 5 carbon atoms;

in the formula (c-1-2),

X 2 is a single bond or a hydrocarbon group having 1 to 5 carbon atoms and —CH 2 — constituting the hydrocarbon group may be replaced by —O— or —C(═O)—;

n5 is an integer of 1 to 4;

R 16 is a hydrocarbon group which is linear having 1 to 10 carbon atoms, or branched or cyclic having 3 to 10 carbon atoms, —CH 2 — constituting the hydrocarbon group may be replaced by —O—, —C(═O)—O— or —C(═O)—, or a hydrogen atom constituting the hydrocarbon group may be substituted with a halogen atom or a hetero atom;

in the formula (c-1-3),

X 3 is a single bond or a hydrocarbon group having 1 to 5 carbon atoms and —CH 2 — constituting the hydrocarbon group may be replaced by —O— or —C(═O)—;

n6 is an integer of 1 to 4; and

R 17 is a hydrocarbon group which is linear having 1 to 10 carbon atoms, or branched or cyclic having 3 to 10 carbon atoms, —CH 2 — constituting the hydrocarbon group may be replaced by —O—, —C(═O)—O— or —C(═O)—, or a hydrogen atom constituting the hydrocarbon group may be substituted with a halogen atom or a hetero atom.

4. The resist composition according to claim 1 , wherein the salt represented by the general formula (B) is a salt represented by the following formula (B1):

in the formula (B1),

R 18 to R 19 each independently represent a hydrogen atom, a fluorine atom or a trifluoromethyl group;

R 20 represents a hydrogen atom, a hydroxyl group, a linear, branched or cyclic, substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 30 carbon atoms; and

M 2+ represents a counter cation having a substituent(s), a sulfonium cation, an iodonium cation or an ammonium cation.

5. The resist composition according to claim 2 , wherein the salt represented by the general formula (B) is a salt represented by the following formula (B1):

in the formula (B1),

R 18 to R 19 each independently represent a hydrogen atom, a fluorine atom or a trifluoromethyl group;

R 20 represents a hydrogen atom, a hydroxyl group, a linear, branched or cyclic, substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 30 carbon atoms; and

M 2+ represents a counter cation having a substituent(s), a sulfonium cation, an iodonium cation or an ammonium cation.

6. The resist composition according to claim 3 , wherein the salt represented by the general formula (B) is a salt represented by the following formula (B1):

in the formula (B1),

R 18 to R 19 each independently represent a hydrogen atom, a fluorine atom or a trifluoromethyl group;

R 20 represents a hydrogen atom, a hydroxyl group, a linear, branched or cyclic, substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 30 carbon atoms; and

M 2+ represents a counter cation having a substituent(s), a sulfonium cation, an iodonium cation or an ammonium cation.

7. The resist composition according to claim 1 , which further comprises a salt represented by the following formula (B2):

in the formula (B2),

R 21 represents a hydrogen atom or a trifluoromethyl group;

R 22 represents a linear, branched or cyclic monovalent hydrocarbon group having 1 to 35 carbon atoms which may contain an oxygen atom(s), and one or more hydrogen atoms bonded to the carbon atom may be substituted with a fluorine atom(s); and

M 2+ represents a counter cation having a substituent(s), a sulfonium cation, an iodonium cation or an ammonium cation.

8. The resist composition according to claim 2 , which further comprises a salt represented by the following formula (B2):

in the formula (B2),

R 21 represents a hydrogen atom or a trifluoromethyl group;

R 22 represents a linear, branched or cyclic monovalent hydrocarbon group having 1 to 35 carbon atoms which may contain an oxygen atom(s), and one or more hydrogen atoms bonded to the carbon atom may be substituted with a fluorine atom(s); and

M 2+ represents a counter cation having a substituent(s), a sulfonium cation, an iodonium cation or an ammonium cation.

9. The resist composition according to claim 3 , which further comprises a salt represented by the following formula (B2):

in the formula (B2),

R 21 represents a hydrogen atom or a trifluoromethyl group;

R 22 represents a linear, branched or cyclic monovalent hydrocarbon group having 1 to 35 carbon atoms which may contain an oxygen atom(s), and one or more hydrogen atoms bonded to the carbon atom may be substituted with a fluorine atom(s); and

M 2+ represents a counter cation having a substituent(s), a sulfonium cation, an iodonium cation or an ammonium cation.

10. The resist composition according to claim 1 , wherein the repeating unit represented by the formula (a-2) is a repeating unit represented by the following formula (a-2-1):

in the formula (a-2-1), R 8 to R 11 are as defined above.

11. The resist composition according to claim 2 , wherein the repeating unit represented by the formula (a-2) is a repeating unit represented by the following formula (a-2-1):

in the formula (a-2-1), R 8 to R 11 are as defined above.

12. The resist composition according to claim 3 , wherein the repeating unit represented by the formula (a-2) is a repeating unit represented by the following formula (a-2-1):

in the formula (a-2-1), R 8 to R 11 are as defined above.

13. A patterning process for forming a pattern on a substrate which comprises: forming a resist film on the substrate using the resist composition according to claim 1 , laying a mask over the resist film, exposing the film by irradiating a high energy beam, and then, developing with an alkali developing solution to form a pattern on the substrate, wherein the exposure with the high energy beam is carried out by a KrF excimer laser having a wavelength of 248 nm, an ArF excimer laser having a wavelength of 193 nm, EUV having a wavelength of 13.5 nm, or electron beam.

14. A patterning process for forming a pattern on a substrate which comprises: forming a resist film on the substrate using the resist composition according to claim 2 , laying a mask over the resist film, exposing the film by irradiating a high energy beam, and then, developing with an alkali developing solution to form a pattern on the substrate, wherein the exposure with the high energy beam is carried out by a KrF excimer laser having a wavelength of 248 nm, an ArF excimer laser having a wavelength of 193 nm, EUV having a wavelength of 13.5 nm, or electron beam.

15. A patterning process for forming a pattern on a substrate which comprises: forming a resist film on the substrate using the resist composition according to claim 3 , laying a mask over the resist film, exposing the film by irradiating a high energy beam, and then, developing with an alkali developing solution to form a pattern on the substrate, wherein the exposure with the high energy beam is carried out by a KrF excimer laser having a wavelength of 248 nm, an ArF excimer laser having a wavelength of 193 nm, EUV having a wavelength of 13.5 nm, or electron beam.