NOVEL PHOTOACID GENERATOR, RESIST COMPOSITION, AND PATTERNING PROCESS
First Claim
1. A photoacid generator for chemically amplified resist compositions which generates a sulfonic acid in response to high-energy radiation selected from UV, deep-UV, EUV, electron beam, x-ray, excimer laser, gamma-ray and synchrotron radiation, said sulfonic acid having the general formula (1a) or (1b):
-
R1—
COOCH2CF2SO3−
H+
(1a)
R1—
O—
COOCH2CF2SO3−
H+
(1b)wherein R1 is a monovalent C20-C50 hydrocarbon group of steroid structure which may contain a heteroatom.
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Accused Products
Abstract
Photoacid generators generate sulfonic acids of formula (1a) or (1b) upon exposure to high-energy radiation.
R1—COOCH2CF2SO3−H+ (1a)
R1—O—COOCH2CF2SO3−H+ (1b)
R1 is a monovalent C20-C50 hydrocarbon group of steroid structure which may contain a heteroatom. The bulky steroid structure ensures adequate control of acid diffusion. The photoacid generators are compatible with resins and suited for use in chemically amplified resist compositions.
83 Citations
17 Claims
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1. A photoacid generator for chemically amplified resist compositions which generates a sulfonic acid in response to high-energy radiation selected from UV, deep-UV, EUV, electron beam, x-ray, excimer laser, gamma-ray and synchrotron radiation, said sulfonic acid having the general formula (1a) or (1b):
-
R1—
COOCH2CF2SO3−
H+
(1a)
R1—
O—
COOCH2CF2SO3−
H+
(1b)wherein R1 is a monovalent C20-C50 hydrocarbon group of steroid structure which may contain a heteroatom. - View Dependent Claims (2, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
wherein Z is an oxygen atom or —
O—
(CH2)L—
COO—
, and L is an integer of 1 to 5.
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6. A resist composition comprising a base resin, an acid generator, and an organic solvent, said acid generator comprising a photoacid generator which generates a sulfonic acid having formula (1a) or (1b) as set forth in claim 1.
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7. A resist composition comprising a base resin, an acid generator, and an organic solvent, said acid generator comprising a photoacid generator which generates a sulfonic acid having the following structural formula (1c) or (1d) as set forth in claim 2,
wherein Z is an oxygen atom or — - O—
(CH2)L—
COO—
, and L is an integer of 1 to 5.
- O—
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8. The resist composition of claim 6, wherein said base resin is one or more polymers selected from the group consisting of poly(meth)acrylic acid and derivatives thereof, cycloolefin derivative/maleic anhydride alternating copolymers, copolymers of ternary or more components comprising a cycloolefin derivative, maleic anhydride, and polyacrylic acid or derivatives thereof, cycloolefin derivative/α
- -trifluoromethyl acrylate derivative copolymers, polynorbornene, ROMP polymers, and hydrogenated ROMP polymers.
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9. The resist composition of claim 6, wherein said base resin is a polymeric structure containing silicon atoms.
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10. The resist composition of claim 6, wherein said base resin is a polymeric structure containing fluorine atoms.
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11. The resist composition of claim 6, wherein said base resin is a polymer comprising recurring units of the general formula (8) and/or (12) and recurring units of at least one type selected from the general formulae (9) to (11), (13), and (14):
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wherein R11 is hydrogen, fluorine, methyl or trifluoromethyl, R12 and R13 are each independently hydrogen or hydroxyl, XA is an acid labile group, YL is a substituent group of lactone structure, ZA is hydrogen, C1-C15 fluoroalkyl or C1-C15 fluoroalcohol-containing substituent group, wherein R11 and XA are as defined above, and G is an oxygen atom or carboxyl group (—
C(═
O)O—
).
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12. A chemically amplified positive resist composition comprising a base resin as set forth in claim 8, a photoacid generator which generates a sulfonic acid having formula (1a) or (1b) as set forth in claim 1, and a solvent, wherein said base resin is insoluble or substantially insoluble in a developer, and becomes soluble under the action of the acid.
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13. A chemically amplified positive resist composition comprising a base resin as set forth in claim 8, a photoacid generator which generates a sulfonic acid having formula (1c) or (1d) as set forth in claim 2, and a solvent, wherein said base resin is insoluble or substantially insoluble in a developer, and becomes soluble under the action of the acid.
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14. The chemically amplified positive resist composition of claim 12, further comprising a quencher.
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15. The chemically amplified positive resist composition of claim 12, further comprising a dissolution inhibitor.
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16. A process for forming a pattern comprising the steps of:
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applying the resist composition of claim 6 onto a substrate to form a coating, heat treating the coating and exposing it to high-energy radiation having a wavelength of up to 300 nm through a photomask, and optionally heat treating and developing the exposed coating with a developer.
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17. The process of claim 16, wherein the exposing step relies on immersion lithography comprising directing radiation from an ArF excimer laser having a wavelength of 193 nm through a projection lens, with a liquid such as water, glycerol or ethylene glycol intervening between the coated substrate and the projection lens.
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3. A sulfonium salt having the general formula (2a) or (2b):
-
R1—
COOCH2CF2SO3−
R2R3R4S+
(2a)
R1—
O—
COOCH2CF2SO3−
R2R3R4S+
(2b)wherein R1 is a monovalent C20-C50 hydrocarbon group of steroid structure which may contain a heteroatom, R2, R3 and R4 are each independently a substituted or unsubstituted, straight or branched C1-C10 alkyl, alkenyl or oxoalkyl group or a substituted or unsubstituted C6-C18 aryl, aralkyl or aryloxoalkyl group, or at least two of R2, R3 and R4 may bond together to form a ring with the sulfur atom.
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4. A sulfonium salt having the general formula (3a) or (3b):
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R1—
COOCH2CF2SO3−
(R5(O)n)mPh′
S+Ph2
(3a)
R1—
O—
COOCH2CF2SO3−
(R5(O)n)mPh′
S+Ph2
(3b)wherein R1 is a monovalent C20-C50 hydrocarbon group of steroid structure which may contain a heteroatom, R5 is a substituted or unsubstituted, straight, branched or cyclic C1-C20 alkyl or alkenyl group or a substituted or unsubstituted C6-C14 aryl group, m is an integer of 1 to 5, n is 0 or 1, Ph denotes phenyl, and Ph′
denotes a phenyl group in which a number “
m”
of hydrogen atoms are substituted by R5(O)n—
groups.
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5. A iodonium salt having the general formula (4a) or (4b):
-
R′
—
COOCH2CF2SO3−
((R5(O)n)mPh′
)2I+
(4a)
R1—
O—
COOCH2CF2SO3−
((R5(O)n)mPh′
)2I+
(4b)wherein R1 is a monovalent C20-C50 hydrocarbon group of steroid structure which may contain a heteroatom, R5 is a substituted or unsubstituted, straight, branched or cyclic C1-C20 alkyl or alkenyl group or a substituted or unsubstituted C6-C14 aryl group, m is an integer of 1 to 5, n is 0 or 1, and Ph′
denotes a phenyl group in which a number “
m”
of hydrogen atoms are substituted by R5(O)n—
groups.
-
Specification