Photoresist resin as well as preparation method and application thereof

Abstract

The invention discloses photoresist resin and a preparation method and application thereof.The photoresist resin is prepared from an acid-sensitive monomer a, a polar monomer b and an acrylamide monomer c through a polymerization reaction, and when the photoresist resin is applied to the field of ArF immersed photoetching, leaching of small molecules such as photoacid can be reduced, the contact angle of photoresist can be increased, and water residues can be reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of integrated circuits, and particularly relates to a photoresist resin, a preparation method thereof, and an application thereof. Background Art

[0002] Photoresist, also known as photoresist, is the most critical material in the lithography process. Photoresist generally includes resin, solvent, photoacid generator, dissolution inhibitor, additives, etc. Among them, the resin is called the backbone of the photoresist, and its main function is to generate the difference in solubility of the resin in the exposed and unexposed areas in a specific developer, so as to form a pattern on the silicon wafer. With the development of Moore's Law, the requirement for resolution in integrated circuits is getting higher and higher, and lithography has developed from i-line, KrF, etc. to ArF, EUV. Among them, ArF lithography is divided into dry and immersion types. The most significant feature of the ArF immersion lithography process is the introduction of water between the lens and the photoresist. The presence of water introduces new problems. One is that water may remain on the photoresist, forming defects. The other is that photoacids in the photoresist may be leached out by water, resulting in lithography failure.

[0003] To solve the above problems, the commonly used method at present is to add fluorine-containing additives or fluorine-containing resins. For example, patents CN114349898A and CN115806641A disclose a fluorine-containing resin for photoresist to improve the hydrophobicity of the photoresist surface. However, fluorine monomers are often difficult to obtain and most of them are unstable. Moreover, due to the low surface energy of fluorine-containing additives or fluorine-containing resins and the surface energy difference with the resin, the compatibility of the photoresist system is poor, and it is easy to form clusters and particles, resulting in defects, which to a certain extent affects the lithography performance of the photoresist and the product yield, restricting the development of immersion photoresist. Summary of the Invention

[0004] To solve the above technical problems, the present invention provides a photoresist resin, a preparation method thereof, and an application thereof.

[0005] Based on the first aspect of the present invention, first, a photoresist resin is provided. Through unique structural design and unit content control, when the obtained resin is applied in the field of ArF immersion lithography, it can reduce the leaching of small molecules such as photoacids, and can increase the contact angle of the photoresist and reduce the water residue.

[0006] Based on the second aspect of the present invention, a preparation method of a photoresist resin is also provided. The preparation of the photoresist resin has wide adaptability to the existing synthesis methods in the art.

[0007] Based on the third aspect of the present invention, a photoresist resin composition is also provided. This composition contains a photoresist resin with a unique structural design and has typical performance improvement when applied in the field of ArF immersion lithography.

[0008] Based on the fourth aspect of the present invention, there is also provided an application of a photoresist resin composition in an ArF immersion lithography process.

[0009] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0010] First, a photoresist resin having structural units represented by the following formulas I, II, and III;

[0011]

[0012]

[0013] In the above formula, R1 and R3 are selected from H or a C1-C 10 alkyl group, preferably H or methyl; R2 is selected from a C5-C 20 cycloalkyl group or a cycloalkyl group containing an alkyl substituent, preferably a C6-C 12 monocyclic alkyl group or polycyclic alkyl group containing an alkyl substituent, wherein the alkyl substituent is selected from methyl, ethyl, isopropyl; the carbon atom in R2 connected to the oxygen atom does not contain a hydrogen substituent;

[0014] R4 is selected from a C3-C 10 lactone group, a C5-C 20 cycloalkylcarbonyl lactone, a C5-C 20 hydroxy-substituted cycloalkyl group, a C5-C 20 cycloalkyl group or a cycloalkyl group containing an alkyl substituent, wherein the alkyl substituent is selected from methyl, ethyl, isopropyl; when R4 is selected from a C5-C 20 cycloalkyl group or a cycloalkyl group containing an alkyl substituent, the carbon atom in R4 connected to the oxygen atom contains at least one hydrogen substituent;

[0015] R5 is selected from a C1-C 12 alkyl group, a C6-C 24 aryl group or aralkyl group, preferably a C2-C6 alkyl group, a C6-C 12 aryl group or aralkyl group.

[0016] As a preferred embodiment of the photoresist resin provided by the present invention, its weight average molecular weight is 2,000-100,000, preferably 5,000-30,000.

[0017] As a preferred embodiment of the photoresist resin provided by the present invention, the molar percentage contents of the structural units represented by the formulas I, II, and III are 20-60%, 20-60%, and 5-20% respectively, preferably 40-50%, 40-50%, and 5-15%.

[0018] Secondly, a method for preparing a photoresist resin is obtained by polymerizing an acid-sensitive monomer a, a polar monomer b, and an acrylamide monomer c;

[0019]

[0020] Among them, the selection ranges of R1-R5 in formulas a, b, and c are the same as those of R1-R5 in formulas I, II, and III described above.

[0021] Preferably, the acid-sensitive monomer a can be selected from one or more of 1-isopropylcyclopentyl methacrylate, 2-methyl-2-adamantyl methacrylate, 1-methyl-1-cyclohexyl methacrylate, 2-ethyl-2-adamantyl methacrylate, 1-methylcyclopentyl methacrylate;

[0022] Preferably, the polar monomer b can be selected from one or more of 2-carboxy-4-norbornene lactone-5-methacrylate, 2-carbonyl-tetrahydrofuran-3-hydroxy-methacrylate, 1,7,7-trimethylbicyclo[2.2.1]hept-2-yl methacrylate, r-butyrolactone-3-yl methacrylate, 3-hydroxy-1-adamantyl methacrylate;

[0023] Preferably, the acrylamide monomer c can be selected from one or more of N-butyl acrylamide, N-isopropyl acrylamide, N-propyl acrylamide, N-phenyl acrylamide, N-ethyl acrylamide;

[0024] In the above preparation method, the polymerization reaction can be carried out with reference to any known photoresist resin synthesis technology on the basis of adjusting the raw material monomers. For example, refer to the conventional polymerization methods described in patents JP4905786B2 and EP2428843A1.

[0025] As a preferred embodiment of the preparation method provided by the present invention, based on the total molar amount of all three monomers being 100%, the molar percentages of the acid-sensitive monomer a, the polar monomer b, and the acrylamide monomer c are 20-60%, 20-60%, and 5-20% respectively, preferably 40-50%, 40-50%, and 5-15%.

[0026] As a preferred embodiment of the preparation method provided by the present invention, the raw materials for the polymerization reaction further include a radical initiator, and the amount of the radical initiator is 0.5-2% of the total molar amount of all three monomers.

[0027] Furthermore, the radical initiator is selected from one or more of azobisisobutyronitrile, azobisisoheptonitrile, and azobisisopentanenitrile.

[0028] Preferably, the polymerization reaction conditions are as follows: under a closed condition, reacting at 60 - 90 °C for 3 - 8 h.

[0029] Preferably, the polymerization reaction is carried out in the presence of a solvent. Optionally, the solvent is, for example, one or more of propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, 2 - butanone, ethyl lactate, and methyl isopentyl ketone.

[0030] Again, a photoresist resin composition comprising the photoresist resin described above.

[0031] Specifically, a photoresist resin composition, by mass percentage, comprises the following components:

[0032] Photoresist resin: 1 - 20%, preferably 2 - 10%;

[0033] Photoacid generator: 0.1 - 10%, preferably 0.5 - 3%;

[0034] Acid diffusion inhibitor: 0.1 - 10%, preferably 0.5 - 2%;

[0035] Organic solvent: 60 - 98%, preferably 85 - 95%.

[0036] As a preferred embodiment of the photoresist resin composition provided by the present invention, the photoacid generator is selected from one or more of sulfonium salts and iodonium salts, preferably one or more of triphenylsulfonium perfluorobutanesulfonate, triphenylsulfonium trifluoromethanesulfonate, (4 - tert - butylphenyl)diphenylsulfonium camphorsulfonate, bis(4 - tert - butylphenyl)iodonium perfluorobutanesulfonate, the salt of bis[4 - (1,1 - dimethylethyl)phenyl]iodonium and trifluoromethanesulfonic acid, and bis(4 - tert - butylphenyl)iodonium camphorsulfonate, and more preferably one or more of triphenylsulfonium perfluorobutanesulfonate, triphenylsulfonium trifluoromethanesulfonate, and bis(4 - tert - butylphenyl)iodonium perfluorobutanesulfonate.

[0037] As a preferred embodiment of the photoresist resin composition provided by the present invention, the acid diffusion inhibitor is an amine compound, preferably selected from one or more of trioctylamine, tetrabutylammonium hydroxide, isopropanolamine, N,N - dimethylaminoethyl acetate, N,N - dimethylglycine, tris(3,6 - dioxaoctyl)amine, 4,4’ - diaminodiphenyl ether, di - n - octylamine, N,N - dimethylformamide, acetamide, N - methylacetamide, and benzamide.

[0038] As a preferred embodiment of the photoresist resin composition provided by the present invention, the organic solvent is selected from one or more of ketone solvents, polyols, alkyl ethers, alkyl acid esters solvents, and amide solvents, preferably selected from acetone, methyl ethyl ketone, cyclohexanone, methyl isopentyl ketone, 2-heptanone, ethylene glycol, diethylene glycol, and mono-methyl, mono-ethyl, mono-propyl, mono-butyl, and mono-phenyl ethers, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate, N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone, and more preferably one or more of 2-heptanone, propylene glycol monomethyl ether, and propylene glycol methyl ether acetate.

[0039] Finally, an application of a photoresist resin composition as described above in an ArF immersion lithography process.

[0040] In the present invention, a certain content of N-acrylamide monomers is introduced into the photoresist resin, which can form hydrogen bonds or hydrophobic aggregation effects between and within the chains, and can achieve gelation transformation with the increase of temperature during the application process, thereby reducing the leaching of small molecules such as photoacid generators and acid diffusion inhibitors outside the photoresist. Moreover, this solution can increase the contact angle of the photoresist and reduce the water residue. Detailed implementation manners

[0041] The following further illustrates the present invention through specific examples. The examples described in the present invention are only for the illustration of the present invention and do not limit the scope of the present invention.

[0042] In the examples and comparative examples of the present invention, the sources of the main raw materials are as follows. Without special instructions, other raw materials and reagents can be obtained through ordinary commercial channels:

[0043] 1-Isopropylcyclopentyl methacrylate, purchased from ENN Energy & Environment Co., Ltd.

[0044] 2-Carboxy-4-norbornanolide-5-methacrylate, purchased from ENN Energy & Environment Co., Ltd.

[0045] 2-Methyladamantyl methacrylate, purchased from ENN Energy & Environment Co., Ltd.

[0046] 2-Oxo-tetrahydrofuran-3-hydroxy-methacrylate, purchased from ENN Energy & Environment Co., Ltd.

[0047] Methyl 1-methyl-1-cyclohexylacrylate, purchased from ENN Energy & Environment Co., Ltd.

[0048] 1,7,7-Trimethylbicyclo[2.2.1]hept-2-yl methacrylate, purchased from ENN Energy & Environment Co., Ltd.

[0049] 2-Ethyl-2-adamantyl methacrylate, purchased from ENN Energy & Resources Co., Ltd.;

[0050] γ-Butyrolactone-3-yl methacrylate, purchased from ENN Energy & Resources Co., Ltd.;

[0051] 1-Methylcyclopentyl methacrylate, purchased from ENN Energy & Resources Co., Ltd.;

[0052] 3-Hydroxy-1-adamantyl methacrylate, purchased from Shanghai Huaenyi New Material Technology Co., Ltd.;

[0053] N-Butylacrylamide, purchased from Shanghai Macklin Biochemical Co., Ltd.;

[0054] N-Isopropylacrylamide, purchased from Beijing J&K Scientific Ltd.;

[0055] N-Propylacrylamide, purchased from Sigma-Aldrich (Shanghai) Trading Co., Ltd.;

[0056] N-Phenylacrylamide, purchased from Beijing J&K Scientific Ltd.;

[0057] N-Ethylacrylamide, purchased from Beijing J&K Scientific Ltd.

[0058]

Example 1

[0059] A photoresist resin is prepared by the following method:

[0060] (1) Prepare monomers: 1-Isopropylcyclopentyl methacrylate (19.63 g), 2-Carboxy-4-norbornenyl-5-methacrylate (22.22 g), N-Butylacrylamide (2.83 g);

[0061] (2) Polymerization reaction: Place 30 g of propylene glycol monomethyl ether acetate (PGMEA) in a three-necked flask, displace nitrogen, and heat to 80 °C. Dissolve the initiator azobisisobutyronitrile (0.36 g) and the above-prepared monomers in 60 g of PGMEA, and add dropwise to the three-necked flask within 3 hours, and keep the reaction at a constant temperature for 2 hours. After the reaction is completed, cool the reactants to room temperature, precipitate in 1.5 kg of methyl tert-butyl ether (MTBE), filter and collect the precipitated polymer, air-dry overnight, then dissolve in 120 g of tetrahydrofuran, and then precipitate in 1.6 kg of MTBE. The final polymer is filtered, air-dried overnight, and vacuum-dried at 60 °C for 48 h to obtain the photoresist resin, denoted as Polymer-A.

[0062]

Example 2

[0063] A photoresist resin is prepared by the following method:

[0064] (1) Prepare monomers: adamantyl 2-methyl-2-methylacrylate (23.43 g), 2-oxo-tetrahydrofuran-3-ylmethyl methacrylate (21.27 g), N-isopropylacrylamide (2.83 g);

[0065] (2) Polymerization reaction: Place 30 g of propylene glycol monomethyl ether (PGME) in a three-necked flask, displace nitrogen, and heat to 60 °C. Dissolve the initiator 2,2'-azobis(2-methylbutyronitrile) (0.31 g) and the above-prepared monomers in 60 g of PGME, and add dropwise to the three-necked flask within 3 hours, and keep the temperature for reaction for 5 hours. After the reaction is completed, cool the reactant to room temperature, precipitate in 1.5 kg of methyl tert-butyl ether (MTBE), filter and collect the precipitated polymer, air-dry overnight, then dissolve in 120 g of tetrahydrofuran, and then precipitate in 1.6 kg of MTBE. The final polymer is filtered, air-dried overnight, and vacuum-dried at 60 °C for 48 h to obtain a photoresist resin, denoted as Polymer-B.

[0066]

Example 3

[0067] A photoresist resin is prepared by the following method:

[0068] (1) Prepare monomers: 1-methyl-1-cyclohexyl methacrylate (18.23 g), 1,7,7-trimethylbicyclo[2.2.1]hept-2-yl methacrylate (17.79 g), N-propylacrylamide (2.83 g);

[0069] (2) Polymerization reaction: Place 30 g of 2-butanone in a three-necked flask, displace nitrogen, and heat to 90 °C. Dissolve the initiator 2,2'-azobis(2-methylvaleronitrile) (0.768 g) and the above-prepared monomers in 60 g of 2-butanone, and add dropwise to the three-necked flask within 2 hours, and keep the temperature for reaction for 1 hour. After the reaction is completed, cool the reactant to room temperature, precipitate in 1.5 kg of methyl tert-butyl ether (MTBE), filter and collect the precipitated polymer, air-dry overnight, then dissolve in 120 g of tetrahydrofuran, and then precipitate in 1.6 kg of MTBE. The final polymer is filtered, air-dried overnight, and vacuum-dried at 60 °C for 48 h to obtain a photoresist resin, denoted as Polymer-C.

[0070]

Example 4

[0071] A photoresist resin is prepared by the following method:

[0072] (1) Prepare monomers: 2-ethyl-2-adamantylmethyl methacrylate (24.84 g), r-butyrolactone-3-yl methacrylate (18.91 g), N-ethylacrylamide (1.1 g);

[0073] (2) Polymerization reaction: Place 30 g of ethyl lactate in a three-necked flask, displace nitrogen, and heat up to 70 °C. Dissolve the initiator azobisisobutyronitrile (0.2 g) and the above-prepared monomers in 60 g of ethyl lactate, and add dropwise to the three-necked flask within 2 hours, then keep the temperature for reaction for 2 hours. After the reaction is completed, cool the reactant to room temperature, precipitate it in 1.5 kg of methyl tert-butyl ether (MTBE), filter and collect the precipitated polymer, air-dry it overnight, then dissolve it in 120 g of tetrahydrofuran, and then precipitate it in 1.6 kg of MTBE. The final polymer is filtered, air-dried overnight, and vacuum-dried at 60 °C for 48 h to obtain a photoresist resin, denoted as Polymer-D.

[0074]

Example 5

[0075] A photoresist resin is prepared by the following method:

[0076] (1) Prepare monomers: 1-methylcyclopentyl methacrylate (16.82 g), 3-hydroxy-1-adamantyl methacrylate (21.01 g), N-phenylacrylamide (4.91 g);

[0077] (2) Polymerization reaction: Place 30 g of methyl isopentyl ketone in a three-necked flask, displace nitrogen, and heat up to 80 °C. Dissolve the initiator azodiisovaleronitrile (0.64 g) and the above-prepared monomers in 60 g of methyl isopentyl ketone, and add dropwise to the three-necked flask within 3 hours, then keep the temperature for reaction for 3 hours. After the reaction is completed, cool the reactant to room temperature, precipitate it in 1.5 kg of methyl tert-butyl ether (MTBE), filter and collect the precipitated polymer, air-dry it overnight, then dissolve it in 120 g of tetrahydrofuran, and then precipitate it in 1.6 kg of MTBE. The final polymer is filtered, air-dried overnight, and vacuum-dried at 60 °C for 48 h to obtain a photoresist resin, denoted as Polymer-E.

[0078]

Comparative Example 1

[0079] A photoresist resin is prepared in a method substantially the same as that of Example 1, except that N-butylacrylamide is not added when preparing the monomers in step (1). The obtained polymer is denoted as Polymer-A1.

[0080]

Comparative Example 2

[0081] A photoresist resin was prepared in substantially the same manner as in Example 1, except that the raw materials prepared in step (1) were: 1-isopropylcyclopentyl methacrylate (19.63 g), 2-carboxy-4-norbornenyl-5-methyl methacrylate (22.22 g), and N-butylacrylamide (1.06 g). The resulting polymer was designated as Polymer-A2.

[0082]

Comparative Example 3

[0083] A photoresist resin was prepared in substantially the same manner as in Example 1, except that the raw material N-butylacrylamide in step (1) was replaced with the same molar amount of N,N-dimethylacrylamide. The resulting polymer was designated as Polymer-A3.

[0084]

Application Example

[0085] Raw materials were prepared according to the formulations of each application example in Table 1, dissolved and stirred for 6 h after mixing, and then filtered through a filter with a pore size of 0.1 μm to obtain a photoresist composition.

[0086] Table 1. Formulations of the photoresist composition in different application examples

[0087]

[0088] Performance test:

[0089] (1) Preparation of a photoresist film: A photoresist film with a dry coating thickness of about 100 nm was prepared using a TEL Track act 8 coating and developing machine.

[0090] (2) Leaching test

[0091] The photoresist film was contacted with flowing deionized water, and the total leaching amounts of the photoacid generator and the acid diffusion inhibitor in the water sample at different contact times of the photoresist were detected by LC-MS method. A standard curve was plotted and the leaching rate was calculated. The results are shown in Table 2.

[0092] Table 2. Test results of the leaching rate

[0093] <![CDATA[Leaching rate / (×10 -12 mol / cm 2 / s)]]> Application Example 1 0.08 Application Example 2 0.07 Application Example 3 0.06 Application Example 4 0.07 Application Example 5 0.04 Comparative Application Example 1 0.78 Comparative Application Example 2 0.62 Comparative Application Example 3 0.75 [[ID=

[0094] (3) Contact angle test

[0095] At room temperature, using deionized water as the liquid and the droplet size of 0.2 - 2 μL, the static contact angle of the photoresist film with respect to water was measured. The above-mentioned photoresist films were tested respectively, and each sample was tested 5 times in parallel to obtain the average value. The results are shown in Table 3 below.

[0096] Table 3. Test results of the contact angle

[0097]

[0098]

[0099] It can be seen from the comparison of the test results that by applying the photoresist resin provided by the present invention, the leaching rate of the photoresist can be reduced by one order of magnitude, and the contact angle increases by about 10°. It can significantly reduce the leaching of small molecules such as photoacid generators and acid diffusion inhibitors outside the photoresist during the exposure of 193nm immersion photoresist. Moreover, the formed protective layer increases the contact angle of the photoresist, reduces the water residue, and reduces the generation of defects during the manufacturing process, which is of great significance for mature and advanced processes in chip manufacturing.

[0100] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the method of the present invention, several improvements and supplements can still be made, and these improvements and supplements should also be regarded as the protection scope of the present invention.

Claims

1. A photoresist resin, characterized in that, It has structural units represented by the following Formula I, Formula II, and Formula III; In the above formula, R1 and R3 are selected from H or C1-C 10 alkyl groups, preferably H or methyl; R2 is selected from C5-C 20 cycloalkyl groups or cycloalkyl groups containing alkyl substituents, preferably C6-C 12 monocyclic or polycyclic alkyl groups containing alkyl substituents, where the alkyl substituents are selected from methyl, ethyl, isopropyl; the carbon atom in R2 connected to the oxygen atom does not contain a hydrogen substituent; R4 is selected from a lactone group of C3-C 10 , a cycloalkylcarbon lactone of C5-C 20 , a hydroxy-substituted cycloalkyl of C5-C 20 , a cycloalkyl of C5-C 20 or a cycloalkyl containing an alkyl substituent, wherein the alkyl substituent is selected from methyl, ethyl, isopropyl; when R4 is selected from a cycloalkyl of C5-C 20 or a cycloalkyl containing an alkyl substituent, the carbon atom in R4 connected to the oxygen atom contains at least one hydrogen substituent; R5 is selected from C1-C 12 alkyl, C6-C 24 aryl or aralkyl, preferably C2-C6 alkyl, C6-C 12 aryl or aralkyl.

2. The photoresist resin according to claim 1, characterized in that, The weight-average molecular weight of the photoresist resin is 2,000 - 100,000, preferably 5,000 - 30,000.

3. The photoresist resin according to claim 1 or 2, characterized in that, The molar percentage contents of the structural units represented by Formula I, Formula II, and Formula III are 20 - 60%, 20 - 60%, and 5 - 20% respectively, preferably 40 - 50%, 40 - 50%, and 5 - 15%.

4. A photoresist resin composition, characterized in that, It includes the photoresist resin according to any one of Claims 1 - 3.

5. The photoresist resin composition according to claim 4, wherein By mass percentage, It includes the following components: Photoresist resin 1 - 20%, preferably 2 - 10%; Photoacid generator 0.1 - 10%, preferably 0.5 - 3%; Acid diffusion inhibitor 0.1 - 10%, preferably 0.5 - 2%; Organic solvent 60 - 98%, preferably 85 - 95%.

6. The photoresist resin composition according to claim 5, characterized in that, The photoacid generator is selected from one or more of sulfonium salts and iodonium salts, preferably one or more of triphenylsulfonium perfluorobutanesulfonate, triphenylsulfonium trifluoromethanesulfonate, (4-tert-butylphenyl)diphenylsulfonium camphorsulfonate, bis(4-tert-butylphenyl)iodonium perfluorobutanesulfonate, the salt of bis[4-(1,1-dimethylethyl)phenyl]iodonium and trifluoromethanesulfonic acid, bis(4-tert-butylphenyl)iodonium camphorsulfonate, more preferably one or more of triphenylsulfonium perfluorobutanesulfonate, triphenylsulfonium trifluoromethanesulfonate, bis(4-tert-butylphenyl)iodonium perfluorobutanesulfonate.

7. The photoresist resin composition according to claim 5 or 6, characterized in that, The acid diffusion inhibitor is an amine compound, preferably selected from one or more of trioctylamine, tetrabutylammonium hydroxide, isopropanolamine, N,N-dimethylaminoethyl acetate, N,N-dimethylglycine, tris(3,6-dioxaheptyl)amine, 4,4'-diaminodiphenyl ether, di-n-octylamine, N,N-dimethylformamide, acetamide, N-methylacetamide, and benzamide.

8. The photoresist resin composition according to claim 5 or 6, wherein The organic solvent is selected from one or more of ketone solvents, polyols, alkyl ethers, alkyl acid esters solvents, amide solvents, preferably selected from acetone, methyl ethyl ketone, cyclohexanone, methyl isopentyl ketone, 2-heptanone, ethylene glycol, diethylene glycol, and mono-methyl, mono-ethyl, mono-propyl, mono-butyl, and mono-phenyl ethers, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate, N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone, more preferably one or more of 2-heptanone, propylene glycol monomethyl ether, and propylene glycol methyl ether acetate.

9. Application of a photoresist resin composition according to any one of Claims 4 - 8 in an ArF immersion lithography process.

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