Positive resist composition and pattern formation method using the same
View Patent ↗A positive resist composition which can be suitably used in an ultramicrolithography process such as production of VLSI or high-capacity microchip and in other photofabrication processes and can ensure good sensitivity, resolution, pattern profile and line edge roughness when irradiated with actinic rays or radiation, particularly, electron beam, X-ray or EUV; and a pattern formation method using the composition, are provided, the positive resist composition comprising (A) a resin comprising a specific acryl-based repeating unit and a specific styrene-based repeating unit, which increases the dissolution rate in an alkali developer by the action of an acid, (B) a compound capable of generating an acid upon irradiation with actinic rays or radiation, and (C) a solvent; and a pattern formation method using the composition.
1. A positive resist composition comprising:
(A) a resin comprising a repeating unit represented by formula (I) and a repeating unit represented by formula (II), the resin increasing the dissolution rate in an alkali developer by the action of an acid;
(B) a compound capable of generating an acid upon irradiation with actinic rays or radiation; and
(C) a solvent:
wherein R 1 represents a hydrogen atom or a hydrocarbon group, R 2 represents a hydrocarbon group, and X represents a single bond or a carbonyl group;
wherein R 3 represents a hydrogen atom, a methyl group or a halogen atom, and R 4 represents a group represented by the following formula (A):
wherein L represents a hydrogen atom, an alkyl group, a cycloalkyl group or an aralkyl group, and Z represents a cycloalkyl group, an aralkyl group, or an alkyl group having a cyclic carbon structure as a substituent,
provided that at least one of R 2 and R 4 is a group capable of decomposing by the action of an acid.
2. The positive resist composition as claimed in claim 1 , wherein R 2 in formula (I) is any one of the following formulae (pI) to (pV):
wherein R 11 represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group or a sec-butyl group,
Z represents an atomic group necessary for forming an alicyclic hydrocarbon group together with the carbon atom,
R 12 to R 16 each independently represents a linear or branched alkyl group having from 1 to 4 carbon atoms or an alicyclic hydrocarbon group, provided that at least one of R 12 to R 14 and either one of R 15 and R 16 represent an alicyclic hydrocarbon group,
R 17 to R 21 each independently represents a hydrogen atom, a linear or branched alkyl group having from 1 to 4 carbon atoms or an alicyclic hydrocarbon group, provided that at least one of R 17 to R 21 represents an alicyclic hydrocarbon group and that either one of R 19 and R 21 represents a linear or branched alkyl group having from 1 to 4 carbon atoms or an alicyclic hydrocarbon group,
R 22 to R 25 each independently represents a linear or branched alkyl group having from 1 to 4 carbon atoms or an alicyclic hydrocarbon group, provided that at least one of R 22 to R 25 represents an alicyclic hydrocarbon group, and R 23 and R 24 may combine with each other to form a ring.
3. The positive resist composition as claimed in claim 1 , wherein the substitution position of —OR 4 in the formula (II) is the para-position of the benzene ring.
4. The positive resist composition as claimed in claim 1 , wherein the resin (A) further comprises a polyhydroxystyrene repeating unit.
5. The positive resist composition as claimed in claim 1 , wherein when —OR 4 in formula (II) is an acid-decomposable group, the resin (A) further comprises a polyhydroxystyrene repeating unit.
6. The positive resist composition as claimed in claim 1 , wherein the solvent (C) is a mixed solvent containing a solvent of the following Group A and at least one solvent selected from the following Groups B and C:
Group A: propylene glycol monomethyl ether acetate,
Group B: propylene glycol monomethyl ether, and ethyl lactate,
Group C: γ-butyrolactone, and propylene carbonate.
7. The positive resist composition as claimed in claim 1 , wherein the solvent (C) is a mixed solvent containing a solvent of the following Group D and at least one solvent selected from the following Groups B and F:
Group D: 2-heptanone,
Group E: propylene glycol monomethyl ether, ethyl lactate, and butyl acetate,
Group F: γ-butyrolactone, and propylene carbonate.
8. The positive resist composition as claimed in claim 1 , which further comprises (D) a surfactant.
9. The positive resist composition as claimed in claim 1 , which further comprises (E) an organic basic compound.
10. A pattern formation method comprising:
(1) forming a resist film from a positive resist composition comprising:
(A) a resin comprising a repeating unit represented by formula (I) and a repeating unit represented by formula (II), the resin increasing the dissolution rate in an alkali developer by the action of an acid;
(B) a compound capable of generating an acid upon irradiation with actinic rays or radiation; and
(C) a solvent:
wherein R 1 represents a hydrogen atom or a hydrocarbon group, R 2 represents a hydrocarbon group, and X represents a single bond or a carbonyl group;
wherein R 3 represents a hydrogen atom, a methyl group or a halogen atom, and R 4 represents a group represented by the following formula (A):
wherein L represents a hydrogen atom, an alkyl group, a cycloalkyl group or an aralkyl group, and Z represents a cycloalkyl group, an aralkyl group, or an alkyl group having a cyclic carbon structure as a substituent,
provided that at least one of R 2 and R 4 is a group capable of decomposing by the action of an acid;
(2) irradiating electron beam, X-ray or EUV on said resist film; and
(3) developing said resist film with an alkali developer.
11. The pattern forming method as claimed in claim 10 , wherein R 2 in formula (I) is any one of the following formulae (pI) to (pV):
wherein R 11 represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group or a sec-butyl group,
Z represents an atomic group necessary for forming an alicyclic hydrocarbon group together with the carbon atom,
R 12 to R 16 each independently represents a linear or branched alkyl group having from 1 to 4 carbon atoms or an alicyclic hydrocarbon group, provided that at least one of R 12 to R 14 and either one of R 15 and R 16 represent an alicyclic hydrocarbon group,
R 17 to R 21 each independently represents a hydrogen atom, a linear or branched alkyl group having from 1 to 4 carbon atoms or an alicyclic hydrocarbon group, provided that at least one of R 17 to R 21 represents an alicyclic hydrocarbon group and that either one of R 19 and R 21 represents a linear or branched alkyl group having from 1 to 4 carbon atoms or an alicyclic hydrocarbon group,
R 22 to R 25 each independently represents a linear or branched alkyl group having from 1 to 4 carbon atoms or an alicyclic hydrocarbon group, provided that at least one of R 22 to R 25 represents an alicyclic hydrocarbon group, and R 23 and R 24 may combine with each other to form a ring.
12. The pattern forming method as claimed in claim 10 , wherein the substitution position of —OR 4 in the formula (II) is the para-position of the benzene ring.
13. The pattern forming method as claimed in claim 10 , wherein the resin (A) further comprises a hydroxystyrene repeating unit.
14. The pattern forming method as claimed in claim 10 , wherein when —OR 4 in formula (II) is an acid-decomposable group, the resin (A) further comprises a hydroxystyrene repeating unit.
15. The pattern forming method as claimed in claim 10 , wherein the solvent (C) is a mixed solvent containing a solvent of the following Group A and at least one solvent selected from the following Groups B and C:
Group A: propylene glycol monomethyl ether acetate,
Group B: propylene glycol monomethyl ether, and ethyl lactate,
Group C: γ-butyrolactone, and propylene carbonate.
16. The pattern forming method as claimed in claim 10 , wherein the solvent (C) is a mixed solvent containing a solvent of the following Group D and at least one solvent selected from the following Groups B and F:
Group D: 2-heptanone,
Group B: propylene glycol monomethyl ether, ethyl lactate, and butyl acetate,
Group F: γ-butyrolactone, and propylene carbonate.
17. The pattern forming method as claimed in claim 10 , which further comprises (D) a surfactant.
18. The pattern forming method as claimed in claim 10 , which further comprises (E) an organic basic compound.