Resist composition and patterning process
A resist composition is provided comprising (A) an additive polymer of acyl-protected hexafluoroalcohol structure, (B) a base polymer having a structure derived from lactone ring, hydroxyl group and/or maleic anhydride, the base polymer becoming soluble in alkaline developer under the action of acid, (C) a photoacid generator, and (D) an organic solvent. The additive polymer is transparent to radiation of wavelength up to 200 nm, and its properties can be tailored by a choice of the polymer structure.
1. A resist composition comprising:
(A) a polymer comprising recurring units of the general formula (1) and recurring units of the general formulae (2a) or (2b),
(B) a base polymer having a structure derived from lactone ring, hydroxyl group and/or maleic anhydride, said base polymer becoming soluble in alkaline developer under the action of acid,
(C) a compound capable of generating an acid upon exposure to high-energy radiation, and
(D) an organic solvent,
wherein R 1 is hydrogen, methyl or trifluoromethyl, R 2a and R 2b are hydrogen or straight, branched or cyclic C 1 -C 15 alkyl, R 2a and R 2b may bond together to form a ring with the carbon atom to which they are attached, R 3 is a single bond or straight, branched or cyclic C 1 -C 15 alkylene, and R 4 is a straight, branched or cyclic C 1 -C 20 alkyl or fluoroalkyl which may contain —O— or —C(═O)—,
wherein R 1 is hydrogen, methyl or trifluoromethyl, R 2a and R 2b are hydrogen or straight, branched or cyclic C 1 -C 15 alkyl, R 2a and R 2b may bond together to form a ring with the carbon atom to which they are attached, and R 5 is hydrogen, a straight, branched or cyclic C 1 -C 15 alkyl or fluoroalkyl, or an acid labile group,
said polymer (A) being added to the resist composition in a total amount of 0.5 to 10 parts by weight per 100 parts by weight of the base polymer (B).
2. The resist composition of claim 1 , further comprising (E) a basic compound.
3. The resist composition of claim 1 , further comprising (F) a dissolution inhibitor.
4. A pattern forming process comprising the steps of:
(1) applying the resist composition of claim 1 onto a substrate to form a resist film,
(2) heat treating the resist film and exposing it to high-energy radiation through a photomask, and
(3) developing the exposed resist film with a developer.
5. A pattern forming process comprising the steps of:
(1) applying the resist composition of claim 1 onto a substrate to form a resist film,
(2) heat treating the coated substrate, and exposing it to high-energy radiation through a photomask while keeping a liquid between a projection lens and the coated substrate, and
(3) developing the exposed resist film with a developer.
6. A pattern forming process comprising the steps of:
(1) applying the resist composition of claim 1 onto a substrate to form a resist film,
(2) forming a protective coating on the resist film,
(3) heat treating the coated substrate, and exposing it to high-energy radiation through a photomask while keeping a liquid between a projection lens and the coated substrate, and
(4) developing the exposed resist film with a developer.
7. The process of claim 5 , wherein the liquid is water.
8. The process of claim 6 , wherein an exposure light source emits high-energy radiation having a wavelength of 180 to 250 nm.
9. A pattern forming process comprising the steps of:
(1) applying the resist composition of claim 1 onto a mask blank to form a coating,
(2) heat treating the coating and irradiating it in vacuum with an electron beam, and
(3) developing the coating with a developer.
10. The composition of claim 1 , wherein the polymer of component (A) is one selected from the group consisting of polymers having the following formulae:
11. A resist composition comprising:
(A) a polymer comprising recurring units of the general formula (1) and recurring units of the general formula (2a),
(B) a base polymer having a structure derived from lactone ring, hydroxyl group and/or maleic anhydride, said base polymer becoming soluble in alkaline developer under the action of acid,
(C) a compound capable of generating an acid upon exposure to high-energy radiation, and
(D) an organic solvent,
wherein R 1 is hydrogen, methyl or trifluoromethyl, R 2a and R 2b are hydrogen or straight, branched or cyclic C 1 -C 15 alkyl, R 2a and R 2b may bond together to form a ring with the carbon atom to which they are attached, R 3 is a single bond or straight, branched or cyclic C 1 -C 15 alkylene, and R 4 is a straight, branched or cyclic C 1 -C 20 alkyl or fluoroalkyl which may contain —O— or —C(═O)—,
wherein R 1 is hydrogen, methyl or trifluoromethyl, R 2a and R 2b are hydrogen or straight, branched or cyclic C 1 -C 15 alkyl, R 2a and R 2b may bond together to form a ring with the carbon atom to which they are attached,
said polymer (A) being added to the resist composition in a total amount of 0.5 to 10 parts by weight per 100 parts by weight of the base polymer (B).
12. A pattern forming process comprising the steps of:
(1) applying the resist composition of claim 11 onto a substrate to form a resist film,
(2) heat treating the resist film and exposing it to high-energy radiation through a photomask, and
(3) developing the exposed resist film with a developer.
13. A pattern forming process comprising the steps of:
(1) applying the resist composition of claim 11 onto a substrate to form a resist film,
(2) heat treating the coated substrate, and exposing it to high-energy radiation through a photomask while keeping a liquid between a projection lens and the coated substrate, and
(3) developing the exposed resist film with a developer.
14. A pattern forming process comprising the steps of:
(1) applying the resist composition of claim 11 onto a substrate to form a resist film,
(2) forming a protective coating on the resist film,
(3) heat treating the coated substrate, and exposing it to high-energy radiation through a photomask while keeping a liquid between a projection lens and the coated substrate, and
(4) developing the exposed resist film with a developer.
15. The process of claim 14 , wherein the liquid is water.
16. The process of claim 14 , wherein an exposure light source emits high-energy radiation having a wavelength of 180 to 250 nm.
17. A pattern forming process comprising the steps of:
(1) applying the resist composition of claim 11 onto a mask blank to form a coating,
(2) heat treating the coating and irradiating it in vacuum with an electron beam, and
(3) developing the coating with a developer.
18. The resist composition comprising:
(A) a polymer comprising recurring units of the general formula (1), recurring units of the general formula (2a) and a recurring unit selected from the general formula (2b), (2c) or (2d),
(B) a base polymer having a structure derived from lactone ring, hydroxyl group and/or maleic anhydride, said base polymer becoming soluble in alkaline developer under the action of acid,
(C) a compound capable of generating an acid upon exposure to high-energy radiation, and
(D) an organic solvent,
wherein R 1 is hydrogen, methyl or trifluoromethyl, R 2a and R 2b are hydrogen or straight, branched or cyclic C 1 -C 15 alkyl, R 2a and R 2b may bond together to form a ring with the carbon atom to which they are attached, R 3 is a single bond or straight, branched or cyclic C 1 -C 15 alkylene, and R 4 is a straight, branched or cyclic C 1 -C 20 alkyl or fluoroalkyl which may contain —O— or —C(═O)—,
wherein R 1 is hydrogen, methyl or trifluoromethyl, R 2a and R 2b are hydrogen or straight, branched or cyclic C 1 -C 15 alkyl, R 2a and R 2b may bond together to form a ring with the carbon atom to which they are attached, R 5 is hydrogen, a straight, branched or cyclic C 1 -C 15 alkyl or fluoroalkyl, or an acid labile group, R 6 is a straight, branched or cyclic C 1 -C 15 fluoroalkyl, and R 7 is an acid labile group,
said polymer (A) being added to the resist composition in a total amount of 0.5 to 10 parts by weight per 100 parts by weight of the base polymer (B).
19. A resist composition comprising:
(A) a polymer selected from the group consisting of polymers having the following formulae:
(B) a base polymer having a structure derived from lactone ring, hydroxyl group and/or maleic anhydride, said base polymer becoming soluble in alkaline developer under the action of acid,
(C) a compound capable of generating an acid upon exposure to high-energy radiation, and
(D) an organic solvent,
said polymer (A) being added to the resist composition in a total amount of 0.5 to 10 parts by weight per 100 parts by weight of the base polymer (B).