Negative resist pattern-forming method, and composition for upper layer film formation

1. A negative resist pattern-forming method comprising:

applying a radiation-sensitive resin composition on a substrate to form a resist film;

applying a composition for upper layer film formation on one face of the resist film to form an upper layer film;

placing a liquid on the upper layer film;

exposing the resist film with an ArF excimer laser; and

developing the resist film after the exposing with a developer solution comprising an organic solvent,

wherein the composition for upper layer film formation comprises an upper-layer polymer component and a solvent,

the upper-layer polymer component comprises:

a no-fluorine-containing polymer comprising no fluorine atom, comprising a first structural unit that is represented by formula (6-1) or formula (6-2), and being dissolvable in the organic solvent; and

a fluorine-containing polymer comprising a second structural unit that is different from the first structural unit and that comprises a fluorine atom,

each structural unit included in the no-fluorine-containing polymer comprises a saturated monocyclic alicyclic hydrocarbon structure or a saturated polycyclic alicyclic hydrocarbon structure, and

a percentage content of the fluorine atom in the upper-layer polymer component is no less than 2% by mass and no greater than 30% by mass:

wherein, in the formula (6-1),

R 21 represents a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group;

L represents a single bond or a divalent organic group having 1 to 20 carbon atoms; and

R 22 represents a monovalent polycyclic alicyclic hydrocarbon group having 3 to 20 ring atoms, wherein the monovalent polycyclic alicyclic hydrocarbon group represented by R 22 is a substituted or unsubstituted adamantyl group, a substituted or unsubstituted tricyclodecyl group, or a substituted or unsubstituted tetracyclododecyl group, and

in the formula (6-2),

R 21′ represents a hydrogen atom or a methyl group;

Y 1 , Y 2 and Y 3 each independently represent a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms;

a is an integer of 1 to 4, wherein in a case where a is no less than 2, a plurality of Y 1 s are identical or different, and a plurality of Y 2 s are identical or different;

L′ represents a single bond or a divalent organic group having 1 to 20 carbon atoms; and

R 22′ represents a monovalent polycyclic alicyclic hydrocarbon group having 3 to 20 ring atoms, wherein at least one hydrogen atom of the monovalent polycyclic alicyclic hydrocarbon group represented by R 22′ is optionally substituted with substituent.

2. The negative resist pattern-forming method according to claim 1 , wherein the radiation-sensitive resin composition comprises a resin-layer polymer component and a radiation-sensitive acid generator, and

the resin-layer polymer component comprises a first polymer that comprises a fluorine atom, and a second polymer that comprises an acid-labile group.

3. The negative resist pattern-forming method according to claim 2 , wherein the composition for upper layer film formation satisfies at least one selected from the group consisting of (i) and (ii):

(i) the composition for upper layer film formation further comprises an acid diffusion inhibiting compound; and

(ii) the upper-layer polymer component comprises a structural unit that comprises an acid diffusion-inhibiting group,

wherein the acid diffusion inhibiting compound comprises a compound represented by formula (1), a compound represented by formula (2), a compound represented by formula (3) or a combination thereof, and

wherein the acid diffusion-inhibiting group comprises a group represented by formula (1′), a group represented by formula (2′-1), a group represented by formula (2′-2), a group represented by formula (3′) or a combination thereof,

wherein, in the formula (1),

R A and R B each independently represent a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, or R A and R B taken together represent an aliphatic heterocyclic structure having 3 to 20 ring atoms together with the nitrogen atom to which R A and R B bond; and

R 1 represents a monovalent hydrocarbon group having 1 to 20 carbon atoms,

in the formula (2),

X + represents a monovalent onium cation; and

Y − represents a monovalent weak acid anion,

in the formula (3),

R 18 , R 19 and R 20 each independently represent a hydrogen atom, or a substituted or unsubstituted linear or branched alkyl group, a substituted or unsubstituted monovalent saturated alicyclic hydrocarbon group, a substituted or unsubstituted monovalent aryl group or a monovalent aralkyl group,

in the formula (1′),

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

R J represents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms,

wherein R J and E optionally taken together represent an aliphatic heterocyclic structure having 3 to 20 ring atoms together with the nitrogen atom to which R J and E bond; and

R 1 ′ represents a monovalent hydrocarbon group having 1 to 20 carbon atoms,

in the formula (2′-1),

X′ + represents a monovalent group that comprises a monovalent onium cation; and

Y′ − represents a monovalent weak acid anion,

in the formula (2′-2),

Y″ − represents a monovalent group that comprises a monovalent weak acid anion; and

X″ + represents a monovalent onium cation, and

in the formula (3′),

E′ represents a single bond or a divalent organic group having 1 to 20 carbon atoms; and

R 28 and R 29 each independently represent a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms,

wherein any two of R 28 , R 29 and E′ optionally taken together represent an aliphatic heterocyclic structure having 3 to 20 ring atoms together with the nitrogen atom to which the any two of R 28 , R 29 and E′ bond.

4. The negative resist pattern-forming method according to claim 1 , wherein the monovalent polycyclic alicyclic hydrocarbon group represented by R 22 in the formula (6-1) or R 22′ in the formula (6-2) does not comprise a hetero atom.

5. The negative resist pattern-forming method according to claim 1 , wherein a proportion of the first structural unit with respect to total structural units constituting the upper-layer polymer component is no less than 50 mol %.

6. The negative resist pattern-forming method according to claim 5 , wherein the proportion of the first structural unit with respect to the total structural units constituting the upper-layer polymer component is no less than 70 mol %.

7. The negative resist pattern-forming method according to claim 1 , wherein a content of the fluorine atom in terms of solid content equivalent of the composition for upper layer film formation is no less than 5% by mass and no greater than 10% by mass.

8. The negative resist pattern-forming method according to claim 1 , wherein the solvent comprises an alcohol solvent, an ether solvent or a combination thereof.

9. The negative resist pattern-forming method according to claim 8 , wherein a total percentage content of the alcohol solvent and the ether solvent in the solvent is no less than 70% by mass.

10. The negative resist pattern-forming method according to claim 1 , wherein a mass ratio of the no-fluorine-containing polymer to the fluorine-containing polymer is no less than 10/90 and no greater than 95/5.

11. The negative resist pattern-forming method according to claim 1 , wherein a proportion of the first structural unit with respect to total structural units constituting the upper-layer polymer component is no less than 20 mol % and no greater than 95 mol %.

12. The negative resist pattern-forming method according to claim 1 , wherein the percentage content of the fluorine atom in the upper-layer polymer component is no less than 5% by mass and no greater than 10% by mass.

13. The negative resist pattern-forming method according to claim 1 , wherein the second structural unit comprises a group represented by formula (7):

wherein, in the formula (7),

R O represents a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms; and

R P and R Q each independently represent a fluorine atom or a fluorinated alkyl group having 1 to 20 carbon atoms.

14. The negative resist pattern-forming method according to claim 1 , wherein the substituent of the monovalent polycyclic alicyclic hydrocarbon group represented by R 22 in the formula (6-1) and R 22′ in the formula (6-2) is a hydrocarbon group having 1 to 10 carbon atoms, a hydroxy group, a cyano group, a nitro group, a sulfanyl group or a carboxy group.

15. The negative resist pattern-forming method according to claim 1 , wherein the substituent of the monovalent polycyclic alicyclic hydrocarbon group represented by R 22 in the formula (6-1) and R 22′ in the formula (6-2) is a methyl group, a cyano group or a carboxy group.

16. The negative resist pattern-forming method according to claim 1 , wherein the monovalent polycyclic alicyclic hydrocarbon group represented by R 22 in the formula (6-1) and R 22′ in the formula (6-2) is unsubstituted.

17. The negative resist pattern-forming method according to claim 1 , wherein a proportion of the first structural unit with respect to total structural units constituting the upper-layer polymer component is no less than 30 mol % and no greater than 80 mol %.

18. The negative resist pattern-forming method according to claim 1 , wherein a proportion of the first structural unit with respect to total structural units constituting the upper-layer polymer component is no less than 35 mol % and no greater than 70 mol %.

19. The negative resist pattern-forming method according to claim 1 , wherein a proportion of the first structural unit with respect to total structural units constituting the no-fluorine-containing polymer is no less than 80 mol %.

20. The negative resist pattern-forming method according to claim 1 , wherein a proportion of the first structural unit with respect to total structural units constituting the no-fluorine-containing polymer is 100 mol %.