Radiation-sensitive resin composition, production method thereof, and resist pattern-forming method

1. A radiation-sensitive resin composition comprising:

a polymer comprising a first structural unit represented by formula (1), and a second structural unit represented by formula (2) and comprising an acid-labile group;

a first acid generating agent which generates a first acid by irradiation with a radioactive ray; and

a second acid generating agent which generates a second acid by irradiation with a radioactive ray, wherein

the first acid, to be generated from the first acid generating agent, disassociates the acid-labile group in the polymer upon heating under a condition involving a temperature of no less than 80° C. and no greater than 140° C. for a time period of 1 minute,

the second acid, to be generated from the second acid generating agent, does not substantially disassociate the acid-labile group under condition,

the polymer is synthesized by a living radical polymerization, the living radical polymerization being reversible addition-fragmentation chain-transfer (RAFT) polymerization, atom transfer radical polymerization (ATRP), or nitroxide-mediated radical polymerization (NMP), the RAFT polymerization being carried out by using a reversible addition-fragmentation chain-transfer agent (RAFT agent) together with a radical polymerization initiator, the RAFT agent being at least one selected from the group consisting of a disulfide, a dithioester, a xanthate, a dithiocarbamate, and a trithiocarbonate, and

a ratio (Mw/Mn) of a polystyrene-equivalent weight average molecular weight of the polymer to a polystyrene-equivalent number average molecular weight of the polymer as determined by gel permeation chromatography is less than 1.5,

wherein,

in the formula (1), Ar represents a group obtained by removing (n+1) hydrogen atoms from an arene having 6 to 20 carbon atoms; R 1 represents a hydroxy group, a sulfanyl group, or a monovalent organic group having 1 to 20 carbon atoms; n is an integer of 0 to 11, wherein in a case in which n is no less than 2, a plurality of R 1 s are identical or different; and R 2 represents a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group, and

in the formula (2), R 3 represents a monovalent group having 1 to 20 carbon atoms and comprising the acid-labile group; Z represents a single bond, an oxygen atom, or a sulfur atom; and R 4 represents a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

2. The radiation-sensitive resin composition according to claim 1 , wherein the Mw/Mn of the polymer is less than 1.35.

3. The radiation-sensitive resin composition according to claim 1 , wherein at least one R 1 in the formula (1) represents a hydroxy group.

4. A radiation-sensitive resin composition comprising:

a polymer comprising a first structural unit represented by formula (1), and a second structural unit represented by formula (2) and comprising an acid-labile group;

a first acid generating agent which generates a first acid by irradiation with a radioactive ray; and

a second acid generating agent which generates a second acid by irradiation with a radioactive ray, wherein

the first acid, to be generated from the first acid generating agent, disassociates the acid-labile group in the polymer upon heating under a condition involving a temperature of no less than 80° C. and no greater than 140° C. for a time period of 1 minute,

the second acid, to be generated from the second acid generating agent, does not substantially disassociate the acid-labile group under the condition, and

the polymer is synthesized by a living radical polymerization, the living radical polymerization being reversible addition-fragmentation chain-transfer (RAFT) polymerization, atom transfer radical polymerization (ATRP), or nitroxide-mediated radical polymerization (NMP), the RAFT polymerization being carried out by using a reversible addition-fragmentation chain-transfer agent (RAFT agent) together with a radical polymerization initiator, the RAFT agent being at least one selected from the group consisting of a disulfide, a dithioester, a xanthate, a dithiocarbamate, and a trithiocarbonate,

wherein,

in the formula (1), Ar represents a group obtained by removing (n+1) hydrogen atoms from an arene having 6 to 20 carbon atoms; R 1 represents a hydroxy group, a sulfanyl group, or a monovalent organic group having 1 to 20 carbon atoms; n is an integer of 0 to 11, wherein in a case in which n is no less than 2, a plurality of R 1 s are identical or different; and R 2 represents a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group, and

in the formula (2), R 3 represents a monovalent group having 1 to 20 carbon atoms and comprising the acid-labile group; Z represents a single bond, an oxygen atom, or a sulfur atom; and R 4 represents a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

5. The radiation-sensitive resin composition according to claim 4 , wherein at least one R 1 in the formula (1) represents a hydroxy group.

6. A resist pattern-forming 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.

7. A method of producing the radiation-sensitive resin composition according to claim 4 , the method comprising:

conducting the living radical polymerization in a monomer composition comprising a first monomer represented by formula (i), and a second monomer represented by formula (ii) and comprising an acid-labile group, to obtain a polymer; and

mixing the polymer, a first acid generating agent which generates a first acid by irradiation with a radioactive ray, and a second acid generating agent which generates a second acid by irradiation with a radioactive ray,

wherein

the first acid, to be generated from the first acid generating agent, disassociates the acid-labile group in the polymer upon heating under a condition involving a temperature of no less than 80° C. and no greater than 140° C. for a time period of 1 minute, and

the second acid, to be generated from the second acid generating agent, does not substantially disassociate the acid-labile group under the condition,

wherein,

in the formula (i), Ar represents a group obtained by removing (n+1) hydrogen atoms from an arene having 6 to 20 carbon atoms; R 1 represents a hydroxy group, a sulfanyl group, or a monovalent organic group having 1 to 20 carbon atoms; n is an integer of 0 to 11, wherein in a case in which n is no less than 2, a plurality of R 1 s are identical or different; and R 2 represents a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group, and

in the formula (ii), R 3 represents a monovalent group having 1 to 20 carbon atoms and comprising the acid-labile group; Z represents a single bond, an oxygen atom, or a sulfur atom; and R 4 represents a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

8. The method according to claim 7 , wherein a ratio (Mw/Mn) of a polystyrene-equivalent weight average molecular weight of the polymer to a polystyrene-equivalent number average molecular weight of the polymer as determined by gel permeation chromatography is less than 1.5.

9. The method according to claim 8 , wherein the Mw/Mn of the polymer is less than 1.35.

10. The method according to claim 7 , wherein at least one R 1 in the formula (i) represents a hydroxy group.

11. A resist pattern-forming method comprising:

applying the radiation-sensitive resin composition according to claim 4 directly or indirectly on a substrate to form a resist film;

exposing the resist film; and

developing the resist film exposed.

12. The method according to claim 11 , wherein a ratio (Mw/Mn) of a polystyrene-equivalent weight average molecular weight of the polymer to a polystyrene-equivalent number average molecular weight of the polymer as determined by gel permeation chromatography is less than 1.5.

13. The resist pattern-forming method according to claim 12 , wherein the Mw/Mn of the polymer is less than 1.35.

14. The resist pattern-forming method according to claim 11 , wherein at least one R 1 in the formula (1) represents a hydroxy group.