Resin for immersed ArF photoresist, preparation method and immersed ArF photoresist

Abstract

The invention is suitable for the technical field of semiconductors, and provides resin for an immersed ArF photoresist, a preparation method and the immersed ArF photoresist. The preparation method comprises the following steps: adding a fluorine-containing initiator, cuprous halide, a ligand, ethyl cyclopentanol methacrylate, hydroxy adamantyl methacrylate, butyrolactone methacrylate and a reaction solvent into a reaction container, and carrying out thermal polymerization reaction to obtain the resin for the immersed ArF photoresist. In this way, fluorine is introduced into the resin through the fluorine-containing initiator, the resin for the immersed ArF photoresist can be directly used as a resin component in the photoresist, other resin does not need to be used, and the prepared photoresist is clearer in line and better in performance.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductors, and in particular relates to a resin for immersion ArF photoresist, a preparation method and the immersion ArF photoresist. Background Art

[0002] Photoresist (also known as resist composition) is an indispensable raw material for manufacturing semiconductor chips. When preparing chips, photoresist can transfer the fine pattern on the mask to the substrate through processes such as coating, baking, exposure, development, and etching. The shorter the exposure wavelength, the higher the resolution of the photoresist. The exposure wavelength has gone through the development process of G line (436nm), I line (365nm), KrF (248nm), ArF&ArFi (193nm&134nm), and EUV (13.5nm), and the photolithography process has continued to improve. At present, ArF immersion lithography is widely used in the preparation of mid-to-high-end chips.

[0003] The existing formula of ArF immersion photoresist consists of resin, photoacid generator, quencher, etc. The most common photoacid generators are ionic sulfonium salts and iodonium salts. Such photoacid generators have a certain solubility in deionized water. When applied to immersion lithography process technology, the photoacid generator can precipitate from the photoresist and dissolve into the filling medium deionized water, which will contaminate the lens of the lithography machine on the one hand, and affect the formula ratio of the photoresist on the other hand, thereby affecting the exposure reaction and lithography pattern.

[0004] In order to prevent the effective components of the photoresist from dissolving out, the prior art applies a top coating layer (topcoat layer) on the photoresist to prevent the photoacid generator and other water-soluble components from entering the deionized water; or, a hydrophobic polymer compound with alkali solubility is added to the photoresist, and the hydrophobic polymer compound can automatically generate a protective layer on the surface of the photoresist during the photoresist coating process, playing the role of the topcoat layer. However, these two methods have the problems of complex process, high process difficulty, or the hydrophobic polymer compound does not match the main resin of the photoresist, which affects the quality of photolithography exposure. Summary of the invention

[0005] In view of the above problems, the present invention provides a resin for immersion ArF photoresist, a preparation method and immersion ArF photoresist. The preparation method can obtain a resin for immersion ArF photoresist. When the resin for immersion ArF photoresist is used to prepare photoresist, no other resin needs to be added. The resin for immersion ArF photoresist contains fluorine end groups, which can be gathered on the surface of the photoresist to play the role of a topcoat layer. At the same time, there is no problem of mismatch between hydrophobic polymer compounds and the main resin of the photoresist.

[0006] In one aspect of the present invention, a method for preparing a resin for immersion ArF photoresist is provided, the method comprising:

[0007] A fluorine-containing initiator, cuprous halide, a ligand, ethyl cyclopentanol methacrylate, hydroxyadamantyl methacrylate, butyrolactone methacrylate and a reaction solvent are added into a reaction container, and the reaction is heated at 60° C. to 80° C. for 6 h to 8 h. After the reaction is completed, copper ions are removed by column chromatography, and then precipitation treatment is performed by an organic solvent to obtain a resin for immersion ArF photoresist.

[0008] Another aspect of the present invention provides an immersion ArF photoresist resin obtained by the above-mentioned preparation method, characterized in that the structure of the fluorine-containing resin part in the immersion ArF photoresist resin is as follows:

[0009]

[0010] In the formula, R1 is hydrogen, methyl or ethyl, R2 is hydrogen, methyl or ethyl, R3 is hydrogen, methyl or ethyl, R4 is butyrolactone, R5 is ethylcyclopentanol, R6 is hydroxyadamantane, m, n, x are the molar ratios of monomers, m:n:x=0.2-0.5:0.2-0.5:0.1-0.3, and m+n+x=1.

[0011] Another aspect of the present invention provides an immersion photoresist, which includes: the aforementioned immersion ArF photoresist resin, a photoacid generator, a quencher, and an organic solvent.

[0012] Compared with the prior art, the present application provides a resin for immersion ArF photoresist, a preparation method and an immersion ArF photoresist in various aspects, and these aspects can achieve at least one of the following beneficial effects: the preparation method prepares an immersion ArF photoresist by thermal polymerization, and uses a fluorine-containing initiator to introduce fluorine in the reaction, so that a fluorine-containing end group is formed in the immersion ArF photoresist resin, which can be directly used for the preparation of immersion photoresist. The introduction of fluorine by a fluorine-containing initiator can also well control the amount of fluorine on the polymer chain. Because the obtained immersion ArF photoresist resin contains only one type of resin, there is no problem of mismatch between the two resins. The immersion ArF photoresist is prepared by the immersion ArF photoresist resin of the present application, and the fluorine-containing end group part of the resin can be enriched on the surface during the immersion photolithography process to form an isolation layer, which can effectively inhibit the effective water-soluble components such as photoacid generators in the photoresist from entering the water, so that the lines of the pattern formed by the photoresist are clear and the effect is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 Schematic diagram of the existing fluorine-containing resin and the main resin after photoresist spin coating;

[0014] Figure 2 Schematic diagram of the immersion ArF photoresist resin after spin coating of the present application;

[0015] Figure 3 Photolithography topography of Example 1;

[0016] Figure 4 Photolithography topography of Example 4;

[0017] Figure 5 Lithography morphology of Comparative Example 1;

[0018] Figure 6 Photolithography morphology image of Comparative Example 2. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0020] In order to prevent the effective components in the photoresist from transferring to the aqueous medium during the immersion lithography process, the prior art usually adds a small amount of fluorine-containing resin to the conventional photoresist. The fluorine-containing resin polymerizes on the surface of the photoresist to form a water-resistant coating, which plays a role in preventing the photoresist components from transferring to the aqueous medium. Figure 1 The schematic diagram of the photoresist after spin coating of the existing fluorine-containing resin and the main resin in the immersion photolithography process is shown in FIG. The substrate layer 1 has an anti-reflection coating 2, and then coated with a photoresist layer 4. In the photoresist layer 4, the fluorine-containing resin gathers on the surface to form an isolation layer 3, which plays a role in preventing the photoresist components from entering the water, and part of the fluorine-containing resin will also be blocked in the main resin. For example, CN112898185A discloses a fluorine-containing compound for immersion photoresist, which is added to a conventional photoresist and fully stirred to prepare a fluorine-containing photoresist, wherein the fluorine-containing compound plays a role as a top coating to prevent the photoresist components from transferring to the water medium. CN117683157A, CN117683157A, etc. disclose similar fluorine-containing resins and immersion photoresists. The main component of conventional photoresist is the main resin. When the fluorine-containing resin is mixed with the main resin, there may be a mismatch problem between the two resins, which affects the morphology of the photoresist. Mixing the two resins also makes the photoresist formula more complicated and increases the process difficulty. At the same time, when preparing the fluorine-containing resin in the prior art, the fluorine-containing monomer is polymerized with other monomers. During the polymerization, the fluorine-containing monomer competes with the other monomers, affecting the mutual reactivity ratio, and it is difficult to obtain an ideal resin. The present invention starts from a different direction and provides a resin for immersion ArF photoresist, a preparation method and an immersion ArF photoresist.

[0021] An embodiment of the present invention provides a method for preparing a resin for immersion ArF photoresist, the method comprising:

[0022] A fluorine-containing initiator, cuprous halide, a ligand, ethyl cyclopentanol methacrylate, hydroxyadamantyl methacrylate, butyrolactone methacrylate and a reaction solvent are added into a reaction container, and the reaction is heated at 60° C. to 80° C. for 6 h to 8 h. After the reaction is completed, copper ions are removed by column chromatography, and then precipitation treatment is performed by an organic solvent to obtain a resin for immersion ArF photoresist.

[0023] In the prior art, fluorine-containing monomers compete with main monomers such as ethyl cyclopentanol methacrylate during the polymerization process, and the fluorine-containing monomers will be irregularly distributed in the resin polymer chain, which is not conducive to their enrichment on the silicon wafer surface during spin coating on the silicon wafer surface. On the other hand, it is also not conducive to the resin lithography process and affects the lithography effect.

[0024] The present application introduces fluorine into the resin through a fluorine-containing initiator, which will not affect the reactivity ratio between the resin monomers, so that a polymer chain with regular arrangement of each unit is obtained, thereby obtaining a fluorine-containing resin with a narrower molecular weight distribution and a structure consistent with expectations, and the fluorine-containing group of the fluorine-containing initiator will be transferred to the end of the polymer chain during the reaction, so that the fluorine is located on the surface of the polymer, which can be enriched on the surface of the silicon wafer during the photoresist spin coating, and the role of the water-resistant layer can be better played. At the same time, the preparation method of the present application can accurately control the amount of fluorine on each polymer chain in the resin, and the preparation process parameters are easy to adjust, and it is easier to obtain a resin with an expected structure.

[0025] like Figure 2 This is a schematic diagram of the photoresist containing the immersion ArF photoresist resin of the present application after spin coating during the immersion lithography process. An anti-reflective coating 2 is provided on a substrate layer 1, which is then coated with a photoresist layer 4. In the photoresist layer 4, the fluorine-containing end groups on the polymer chain of the immersion ArF photoresist resin are aggregated on the surface to form an isolation layer 3, which prevents the photoresist components from entering the water.

[0026] In some embodiments, the fluorine-containing initiator is:

[0027]

[0028] In the formula, A is -CH2(CF2)yCF2H or -CH2(CF2)zCF3, 1≤y≤7, 1≤z≤7.

[0029] In some embodiments, the cuprous halide is one or both of cuprous bromide and cuprous chloride.

[0030] In some embodiments, the ligand is one or both of bipyridine and pentamethyldiethylenetriamine.

[0031] In some embodiments, the reaction solvent is one or both of propylene glycol methyl ether acetate and methyl ethyl ketone.

[0032] In some embodiments, the weight ratio of the fluorine-containing initiator, cuprous halide, ligand, ethyl cyclopentanol methacrylate, hydroxyadamantyl methacrylate, and butyrolactone methacrylate added to the reaction container is 0.3-1: 0.2-0.8: 0.5-2: 30-50: 20-40: 20-40. At this ratio, the reaction can make full use of each reaction reagent to generate an immersion ArF photoresist resin with a weight average molecular weight of less than 10,000, a narrower molecular weight distribution, and a polymerization degree that meets expectations.

[0033] In some embodiments, the weight of the reaction solvent added to the reaction container accounts for 20% to 40% of the total weight of all materials added.

[0034] An embodiment of the present invention provides a resin for immersion ArF photoresist, which is obtained by the above-mentioned preparation method, wherein the structure of the fluorine-containing resin part is as follows:

[0035]

[0036] In the formula, R1 is hydrogen, methyl or ethyl, R2 is hydrogen, methyl or ethyl, R3 is hydrogen, methyl or ethyl, R4 is butyrolactone, R5 is ethylcyclopentanol, R6 is hydroxyadamantane, m, n, x are monomer molar ratios, m:n:x=0.2-0.5:0.2-0.5:0.1-0.3, and m+n+x=1. The immersion ArF photoresist resin is equivalent to the composite resin of the main resin and the fluorine-containing resin in the prior art, which makes the photoresist formula simpler and does not have the problem of mismatch between the two resins.

[0037] In some embodiments, the weight average molecular weight of the immersion ArF photoresist resin is less than 10000. Preferably, the weight average molecular weight of the immersion ArF photoresist resin is 5000-10000, more preferably 7500-9600.

[0038] An embodiment of the present invention provides an immersion ArF photoresist, which includes: the aforementioned immersion ArF photoresist resin, a photoacid generator, a quencher, and an organic solvent.

[0039] In some embodiments, the photoacid generator is one or more of diazonium salts, sulfonium salts, iodonium salts, sulfonyldiazomethane, imide sulfonate, nitrobenzylbenzenesulfonate, and sulfonic acid oxime esters.

[0040] In some embodiments, the photoacid generator is one of triphenylsulfonium trifluoromethanesulfonate, N-hydroxysuccinimide methanesulfonate, and triphenylsulfonium p-toluenesulfonate.

[0041] In some embodiments, the one or more of the quencher amine compound, sulfonate or carboxylate is preferably at least one of the following compounds: Quencher 1 、 Quencher 2.

[0042] In some embodiments, the organic solvent is at least one of propylene glycol methyl ether acetate and propylene glycol methyl ether.

[0043] The immersion ArF photoresist of the invention is suitable for immersion photolithography technology, and the image lines after exposure and development are clear and the resolution is high.

[0044] Example 1

[0045] The present embodiment provides a method for preparing a resin for immersion ArF photoresist and a resin for immersion ArF photoresist.

[0046] In a 500mL three-necked flask, 0.3g of fluorine-containing initiator, 0.2g of cuprous bromide, 0.5g of bipyridine, 30g of ethyl cyclopentanol methacrylate, 20g of hydroxyadamantyl methacrylate, 20g of butyrolactone methacrylate and 15g of propylene glycol methyl ether acetate were added and mixed thoroughly, nitrogen was introduced into the mixed liquid for deoxygenation, and the mixture was placed in a constant temperature water bath at 70°C for heating and reflux reaction for 6h. After the reaction was completed, the copper ions in the reaction solution were removed by column chromatography, and the reaction solution was then added dropwise to methanol for precipitation, and the precipitate was taken as the immersion ArF photoresist resin.

[0047] Among them, the structure of the fluorinated initiator is as follows:

[0048]

[0049] A: -CH2CF2CF2H.

[0050] Example 2

[0051] The present embodiment provides a method for preparing a resin for immersion ArF photoresist and a resin for immersion ArF photoresist.

[0052] 0.7g of fluorine-containing initiator, 0.5g of cuprous bromide, 1g of pentamethyldiethylenetriamine, 40g of ethyl cyclopentanol methacrylate, 30g of hydroxyadamantyl methacrylate, 30g of butyrolactone methacrylate and 20g of propylene glycol methyl ether acetate were added to a 500mL three-necked flask and mixed thoroughly, nitrogen was introduced into the mixed liquid for deoxygenation, and the mixture was placed in a constant temperature water bath at 60°C for heating and reflux reaction for 7h. After the reaction was completed, the copper ions in the reaction solution were removed by column chromatography, and the reaction solution was then added dropwise to methanol for precipitation, and the precipitate was taken as the immersion ArF photoresist resin.

[0053] Among them, the structure of the fluorinated initiator is as follows:

[0054]

[0055] A: -CH2(CF2)7CF2H.

[0056] Example 3

[0057] The present embodiment provides a method for preparing a resin for immersion ArF photoresist and a resin for immersion ArF photoresist.

[0058] In a 500mL three-necked flask, 1g of fluorinated initiator, 0.8g of cuprous bromide, 1.2g of pentamethyldiethylenetriamine, 50g of ethyl cyclopentanol methacrylate, 40g of hydroxyadamantyl methacrylate, 40g of butyrolactone methacrylate and 30g of propylene glycol methyl ether acetate were added and mixed thoroughly, nitrogen was introduced into the mixed liquid for deoxygenation, and the mixture was placed in a constant temperature water bath at 80°C for heating and reflux reaction for 8h. After the reaction was completed, the copper ions in the reaction solution were removed by column chromatography, and the reaction solution was then added dropwise to methanol for precipitation, and the precipitate was taken as the immersion ArF photoresist resin.

[0059] Among them, the structure of the fluorinated initiator is as follows:

[0060]

[0061] A: -CH2(CF2)4CF3.

[0062] Example 4

[0063] The present embodiment provides a method for preparing a resin for immersion ArF photoresist and a resin for immersion ArF photoresist.

[0064] In a 500mL three-necked flask, 1g of fluorinated initiator, 0.8g of cuprous bromide, 2g of pentamethyldiethylenetriamine, 40g of ethyl cyclopentanol methacrylate, 30g of hydroxyadamantyl methacrylate, 30g of methyl butyrolactone and 30g of propylene glycol methyl ether acetate were added and mixed thoroughly, nitrogen was introduced into the mixed liquid for deoxygenation, and the mixture was placed in a constant temperature water bath at 70°C for heating and reflux reaction for 8h. After the reaction was completed, the copper ions in the reaction solution were removed by column chromatography, and the reaction solution was then added dropwise to methanol for precipitation, and the precipitate was taken as the immersion ArF photoresist resin.

[0065] Among them, the structure of the fluorinated initiator is as follows:

[0066]

[0067] A: -CH2(CF2)7CF3.

[0068] Example 5

[0069] The present embodiment provides a method for preparing a resin for immersion ArF photoresist and a resin for immersion ArF photoresist.

[0070] In a 500mL three-necked flask, 1g of fluorinated initiator, 0.8g of cuprous bromide, 1.2g of pentamethyldiethylenetriamine, 55g of ethyl cyclopentanol methacrylate, 45g of hydroxyadamantyl methacrylate, 45g of butyrolactone methacrylate and 30g of propylene glycol methyl ether acetate were added and mixed thoroughly, nitrogen was introduced into the mixed liquid for deoxygenation, and the mixture was placed in a constant temperature water bath at 80°C for heating and reflux reaction for 8h. After the reaction was completed, the copper ions in the reaction solution were removed by column chromatography, and the reaction solution was then added dropwise to methanol for precipitation, and the precipitate was taken as the immersion ArF photoresist resin.

[0071] Among them, the structure of the fluorinated initiator is as follows:

[0072]

[0073] A: -CH2(CF2)4CF3.

[0074] Comparative Example 1

[0075] This comparative example uses an existing non-fluorine-containing initiator to prepare the obtained resin.

[0076] 0.3g (1-bromoethyl) benzene, 2g cuprous bromide, 0.5g bipyridine, 30g ethyl cyclopentanol methacrylate, 20g hydroxyadamantyl methacrylate, 20g methyl methacrylate butyrolactone and 15g propylene glycol methyl ether acetate were added to a 500mL three-necked flask and mixed thoroughly, nitrogen was introduced into the mixed liquid for deoxygenation, and the mixture was placed in a constant temperature water bath at 70°C for heating and reflux reaction for 6h. After the reaction was completed, the copper ions in the reaction solution were removed by column chromatography, and the reaction solution was then added dropwise to methanol for precipitation, and the precipitate was taken to obtain the resin.

[0077] Comparative Example 2

[0078] In this comparative example, a resin is prepared using an existing non-fluorine-containing initiator, and a fluorine-containing resin is added to the resin to obtain a mixed resin.

[0079] 0.3g (1-bromoethyl) benzene, 2g cuprous bromide, 0.5g bipyridine, 30g ethyl cyclopentanol methacrylate, 20g hydroxyadamantyl methacrylate, 20g methyl methacrylate butyrolactone and 15g propylene glycol methyl ether acetate were added to a 500mL three-necked flask and mixed thoroughly, nitrogen was introduced into the mixed liquid for deoxygenation, and the mixture was placed in a constant temperature water bath at 70°C for heating and reflux reaction for 6h. After the reaction was completed, the copper ions in the reaction solution were removed by column chromatography, and the reaction solution was then added dropwise to methanol for precipitation, and the precipitate was taken to obtain the resin.

[0080] Another fluorine-containing resin is added to the obtained resin. The fluorine-containing resin is obtained according to the preparation method in CN 112898185A. The proportion of the added fluorine-containing resin is 2%.

[0081] The resins synthesized in Examples 1 to 5, Comparative Examples 1 and 2 were measured for weight average molecular weight and molecular weight distribution by gel chromatography. The results are shown in Table 1 below.

[0082] Resins of Examples 1 to 5, Comparative Examples 1 and 2 were taken for immersion lithography. The photoresist formulation was: 1.5 g of resin (resin in each example or comparative example), 0.1 g of sulfonium salt, 0.06 g of quencher 1, 30 g of propylene glycol methyl ether acetate, and 10 g of propylene glycol methyl ether. The static contact angle of each formulation was tested, and the results are shown in Table 1.

[0083] Contact angle test method: The polymer solution was coated on an 8-inch silicon wafer, and PAB was applied at 100°C for 60 seconds to form a 100nm thick coating. The dynamic contact angle was tested using an SDC-100 contact angle meter. The coating was developed in a TMAH aqueous solution for 60 seconds, rinsed with deionized water for 30 seconds, and the static contact angle after development was tested.

[0084] Photolithography process conditions: 110°C baking for 2 min, exposure energy: 45 mj / cm2, development time 60 s. The photoresist morphology effect corresponding to Example 1 is as follows Figure 3 , the photoresist morphology effects corresponding to Example 2, Example 3, and Example 4 are Figure 3 The photoresist morphology effect corresponding to Example 5 is as follows Figure 4 The photoresist morphology effects corresponding to Comparative Example 1 and Comparative Example 2 are as follows: Figure 5 , Figure 6 shown.

[0085] Table 1

[0086] Group Weight average molecular weight Molecular weight distribution Photoresist contact angle / ° Example 1 7515 1.25 88 Example 2 8223 1.31 92 Example 3 9641 1.40 90 Example 4 8816 1.35 91 Example 5 10542 1.43 82 Comparative Example 1 7718 1.26 78 Comparative Example 2 7718 1.26 90

[0087] From the results in the table, it can be seen that the molecular weight distribution of the resin obtained by the preparation method of the immersion ArF photoresist resin of the present application is narrow. When the resin is used as the only resin to prepare the photoresist, the contact angle of the photoresist is large and the hydrophobicity is good, which can prevent the components in the photoresist from entering the water. Compared with Comparative Example 1, the contact angles of the photoresists of Examples 1 to 5 are significantly larger, which confirms that the use of fluorine-containing initiators can obtain fluorine-terminated resins, which can effectively increase the contact angle of the photoresist.

[0088] Depend on Figure 3-Figure 4 It can be seen that the photoresist prepared by using the immersion ArF photoresist resin of the present application has clear lines after the photolithography process, which is significantly better than that of comparative example 1 ( Figure 5 ), compared with Comparative Example 2 ( Figure 6 ) are basically the same, which further illustrates that the resin for immersion ArF photoresist of the present application can be used to prepare immersion ArF photoresist without adding other resins.

[0089] in addition, Figure 3 Line ratio Figure 4 Clearer and smoother. This is because the weight average molecular weight of the immersion ArF photoresist resin prepared in the embodiment exceeds 1000. The experimental process unexpectedly found that when a fluorine-containing initiator is used to prepare the resin of the present application, when the weight average molecular weight of the resin is too large, exceeding 10000, the contact of the photoresist prepared therefrom will be reduced, and the line clarity after the photolithography process will also decrease. This may be because as the polymer chain becomes longer, the proportion of the fluorine-containing end group becomes smaller, which is not conducive to the diffusion of the fluorine-containing end group to the surface, affecting the hydrophobic effect and ultimately affecting the photolithography effect. Therefore, it is better when the weight average molecular weight of the immersion ArF photoresist resin is less than 10000.

[0090] It is understandable that those skilled in the art can, under the guidance of the above embodiments, combine various implementation methods in the above embodiments to obtain technical solutions of multiple implementation methods.

[0091] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a resin for immersion ArF photoresist, characterized in that: The method comprises: A fluorine-containing initiator, cuprous halide, a ligand, ethyl cyclopentanol methacrylate, hydroxyadamantyl methacrylate, butyrolactone methacrylate and a reaction solvent are added into a reaction container, and the reaction is heated at 60° C. to 80° C. for 6 h to 8 h. After the reaction is completed, copper ions are removed by column chromatography, and then precipitation treatment is performed by an organic solvent to obtain a resin for immersion ArF photoresist.

2. The preparation method according to claim 1, characterized in that The fluorine-containing initiator is: In the formula, A is -CH2(CF2)yCF2H or -CH2(CF2)zCF3, 1≤y≤7, 1≤z≤7.

3. The preparation method according to claim 1, characterized in that: The cuprous halide is one or both of cuprous bromide and cuprous chloride.

4. The preparation method according to claim 1, characterized in that: The ligand is one or both of bipyridine and pentamethyldiethylenetriamine.

5. The preparation method according to claim 1, characterized in that: The reaction solvent is one or both of propylene glycol methyl ether acetate and methyl ethyl ketone.

6. The preparation method according to claim 1, characterized in that: The weight ratio of the fluorine-containing initiator, cuprous halide, ligand, ethyl cyclopentanol methacrylate, hydroxyadamantyl methacrylate and butyrolactone methacrylate added into the reaction container is 0.3-1: 0.2-0.8: 0.5-2: 30-50: 20-40: 20-40.

7. The preparation method according to claim 1, characterized in that: The weight of the reaction solvent added to the reaction container accounts for 20% to 40% of the total weight of all materials added.

8. A resin for immersion ArF photoresist obtained by the preparation method according to any one of claims 1 to 7, characterized in that: The structure of the fluorine-containing resin part in the immersion ArF photoresist resin is as follows: In the formula, R1 is hydrogen, methyl or ethyl, R2 is hydrogen, methyl or ethyl, R3 is hydrogen, methyl or ethyl, R4 is butyrolactone, R5 is ethylcyclopentanol, R6 is hydroxyadamantane, m, n, x are the molar ratios of monomers, m:n:x=0.2-0.5:0.2-0.5:0.1-0.3, and m+n+x=1.

9. An immersion ArF photoresist, characterized in that: The immersion photoresist comprises: the resin for immersion ArF photoresist according to claim 8, a photoacid generator, a quencher, and an organic solvent.

10. The immersion photoresist according to claim 9, characterized in that The photoacid generator is one or more of diazonium salts, sulfonium salts, iodonium salts, sulfonyldiazomethane, imidesulfonate, nitrobenzylbenzenesulfonate, and sulfonic acid oxime esters.

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