Halogen group-containing high-sensitivity self-acid-production photoetching material and preparation method thereof

Abstract

The invention discloses a halogen-group-containing high-sensitivity self-acid-producing photoetching material and a preparation method thereof, and belongs to the technical field of photoetching materials, 4-acetoxystyrene, 4-tert-butoxystyrene, tert-butyl methacrylate and halogen-containing monomers are used as raw materials, and hydrolysis is performed after catalytic free radical polymerization to obtain the halogen-group-containing high-sensitivity self-acid-producing photoetching material. The high-sensitivity self-acid-production photoetching material containing the halogen group is obtained. The high-sensitivity self-acid-production photoetching material provided by the invention shows exposure self-acid production, high sensitivity and excellent pattern transfer capability, and can realize accurate exposure of a non-deformation pattern under the line width of 40nm; and the compound can be used as an additive of a novel photoacid generator, a single-component semiconductor photoresist and a peripheral high-sensitivity requirement material under a high-sensitivity requirement. The method has huge application value in the fields of KrF, electron beam and EUV photoetching process processing and semiconductor integrated circuit photoetching, and meanwhile, the nano manufacturing efficiency can be further improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of lithography materials, and particularly relates to a highly sensitive self - acid - generating lithography material containing halogen groups and a preparation method thereof. Background Art

[0002] Photoresist is an indispensable key material in the field of semiconductor integrated circuits. With the advancement of the integrated circuit technology node, the design of the raw material resin and photo - acid generator corresponding to different application processes of photoresist plays a crucial role. In a typical lithography process, a highly sensitive photoresist is of vital importance as it affects the lithography throughput and directly determines the efficiency of nanomanufacturing. In the currently highly demanded EUV lithography process in the market, due to the power limitation of the light source and multi - layer reflection, the initial power reaching the photoresist is only 2%. Meanwhile, in electron beam lithography, due to the nature of the direct writing process, the chemical reaction time during the writing process determines that the exposure efficiency of the lithography pattern is relatively low. Therefore, improving the sensitivity of the photoresist to achieve manufacturing efficiency is the key point. So far, a large number of research attempts have focused on photoresist systems involving photo - acid generators (PAGs). PAGs generate acid during exposure, and the generation of acid causes a change in solubility, further affecting the de - protection of the photoresist resin to achieve the imaging effect.

[0003] Currently, a large number of literatures have reported the exposure dose required for the sensitivity of photoresists in the existing field. In the research reports, the electron beam exposure dose of photoresists is 10 μC / cm 2 or higher, and the exposure dose required for the photoresists sold in the market is as high as several hundred to several thousand microcoulombs. For example, Yafei Wang introduced a low - molecular - weight negative photoresist containing a bisphenol A main chain (BPA - 6OH). This material has a relatively high glass transition temperature and excellent thermal stability. When exposed in an electron beam lithography system, the exposure sensitivity corresponding to a line pattern with a resolution of about 73.4 nm is 52 μC / cm -2(Yafei W, Long C, Jiating Y, et al. Negative-tone molecular glass photoresist for high-resolution electron beam lithography[J]. Royal Society Open Science, 2021, 8(3): 202132-202132). Yake Wang et al. synthesized and characterized a new molecular glass (TPSiS) incorporating a tetraphenylsilane derivative photoacid generator (sulfonium salt group). For the PSiS resist under electron beam exposure evaluation, the exposure doses required to resolve 25 nm and 16 nm dense line / space patterns by negative tone development (NTD) were 45 and 85 μC / cm 2 (Yake W, Jundi Y, Jinping C, et al. A Single-Component Molecular Glass Resist Based on Tetraphenylsilane Derivatives for Electron Beam Lithography[J]. ACS omega, 2023, 8(13): 12173-12182).

[0004] There are also many patent literatures reporting on the preparation and modification of photoresists. For example: Chinese patent literature CN117215150A discloses an electron beam photoresist and its preparation method. By using polymethyl methacrylate with a high molecular weight as the polymer resin in the electron beam photoresist, its etching resistance and thermal stability are improved on the basis of high resolution, realizing the improvement of comprehensive performance. WO 02 / 069043 A2 discloses a low absorption resist photoresist for 157 nm, providing a single-layer sensitive photoresist with a thickness of about 100 nm to 150 nm for performing high-resolution lithography. JP 2023-153089A discloses a para-agent composition containing an acid generator containing salt and an acid-stable resin containing a specific group structure unit to manufacture a para-pattern with good CD uniformity, which has important application value in semiconductor fine processing. JP2021-95564 A discloses a resin and a para-composition including the resin. The resin of this patent composition can obtain a pattern with good resolution, is suitable for semiconductor fine processing, and has great industrial application value. However, there are still technical problems in the above existing technologies that the component composition in the photoresist cannot better meet the technical requirements of integrated circuits.

[0005] At present, photoresists mainly composed of p-hydroxystyrene resin monomers are widely used in DUV lithography, and are also the main photoresist resin matrices in commercial electron beam and extreme ultraviolet lithography. The research on p-hydroxystyrene resin for photoresists mainly focuses on different chemical modification and polymerization methods such as side chain modification of p-hydroxystyrene resin, bonding photosensitive groups, and adding crosslinking agents to further improve the sensitivity of photoresists. However, the photoresist based on p-hydroxystyrene resin system has a high ultraviolet absorption at 193 nm, which has a great impact on the imaging of thin film photoresists.

[0006] Therefore, on the basis of improving sensitivity and practicability, how to modify and decorate the molecular structure of p-hydroxystyrene resin and provide a new high-sensitivity self-acid-generating photoresist material is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0007] Aiming at the problem of insufficient sensitivity of existing high-resolution photoresists, especially the sensitivity and resolution are limited by the types of protecting groups and acid sensitivity, and to solve the problems such as the demand for the use of chemically amplified photoresists in terms of sensitivity and their applications in electron beam and EUV lithography, the present invention proposes a high-sensitivity self-acid-generating photoresist material containing halogen groups.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] A preparation method of a high-sensitivity self-acid-generating photoresist material containing halogen groups, using 4-acetoxystyrene (PACS), 4-tert-butoxystyrene (PTBS), tert-butyl methacrylate (TBMA) and a halogen-containing monomer as raw materials, and obtaining the high-sensitivity self-acid-generating photoresist material containing halogen groups through catalytic radical polymerization and then hydrolysis.

[0010] Beneficial effects: The present invention provides a high-sensitivity self-acid-generating photoresist material containing halogen groups, which is prepared by simple radical polymerization of 4-hydroxystyrene, 4-tert-butoxystyrene, tert-butyl methacrylate and a monomer with a hexafluoroisopropanol side chain. This material can generate acid by light irradiation without other additives, and then efficiently complete the transfer of lithography images. The advantages of this patterning strategy are further reflected in constructing the image transfer ability only through the chemical modification of the photoresist resin, and at the same time, the efficiency of image transfer can be quantitatively regulated to improve the sensitivity of the photoresist.

[0011] The present invention adopts a radical polymerization method to introduce halogen elements F, Cl and Br with high EUV absorption into the photoresist resin, so as to greatly improve its sensitivity. The sensitivity of the material containing HFIP groups is up to 3 μC / cm at most. 2, almost reaching the minimum exposure dose of an electron beam lithography device, and achieving optimal precise exposure and pattern transfer at a 40-nm line width. The sensitivity is approximately 10 times higher than that of a commercial photoacid generator system. In terms of performance, the high-sensitivity self-producing acid lithography material containing a halogen group provided by the present invention exhibits excellent etching resistance due to the conjugated stabilization effect of the aromatic ring and the formation of a dense carbonized layer. It can finely control the etching rate, optimize the chemical reaction characteristics, and reduce subsequent etching defects on the basis of improving energy utilization efficiency and resolution. Mechanistically, the present invention introduces a halogen-containing monomer structure, such as HFIP. Its strong electrophilicity and the electron-withdrawing effect of fluorine atoms significantly increase the acidity of the photoresist after exposure, enabling imaging without a traditional photoacid generator (PAG), and cooperating with the traditional PAG in a photochemical reaction to reduce the dependence on a single PAG and improve the photoacid generation efficiency. In addition, this material can also be used as the PAG of a chemically amplified photoresist, enriching the types of PAGs and providing a new approach for developing EUV materials with better performance.

[0012] Preferably, the molar ratio of 4-acetoxystyrene, 4-tert-butoxystyrene, tert-butyl methacrylate, and the halogen-containing monomer is 1:(0.06 - 0.36):(0.06 - 0.29):(0.0097 - 0.28).

[0013] More preferably, the molar ratio of 4-acetoxystyrene, 4-tert-butoxystyrene, tert-butyl methacrylate, and the halogen-containing monomer is 1:(0.06 - 0.28):(0.07 - 0.24):(0.08 - 0.028).

[0014] Preferably, the halogen-containing monomer includes one or more of a monomer containing a hexafluoroisopropanol group, a halogenated styrene monomer, and a chloroethyl vinyl ether monomer. The above-mentioned halogen-containing monomers have a larger absorption cross-section under electron beam and EUV exposure, so they have better absorption ability.

[0015] More preferably, the monomer containing a hexafluoroisopropanol group can be an acrylate / methacrylate monomer or a styrene derivative;

[0016] Among them, the general structural formula of the acrylate / methacrylate monomer is CH2=C(R)COO-[linking group]-O-C(CF3)2-R′, and the general structural formula of the styrene derivative is benzene ring-[-O-C(CF3)2-R];

[0017] The halogenated styrene monomer is a monosubstituted halogenated styrene monomer, a disubstituted or polysubstituted halogenated styrene monomer;

[0018] Among them, the general structural formula of the monosubstituted halogenated styrene monomer is CH2=CH-C6H4-X (X = F, Cl, Br);

[0019] The general structural formula of the disubstituted or polysubstituted halogenated styrene monomer is CH2=CH-C6H3-X1X2 (X1, X2 = F, Cl, Br).

[0020] More preferably, the halogenated styrene monomer is A,A-bis(trifluoromethyl)-4-vinylbenzyl alcohol.

[0021] Preferably, the temperature of the catalytic radical polymerization is 55-90 °C and the time is 6-20 h.

[0022] Preferably, in the process of the catalytic radical polymerization, the catalyst used is azobisisobutyronitrile or azobisisoheptonitrile; and / or,

[0023] The mass ratio of the catalyst to 4-acetoxystyrene is (0.009-0.10):1.

[0024] More preferably, the catalyst is azobisisoheptonitrile.

[0025] Beneficial effects: Azobisisoheptonitrile has better catalytic efficiency as a catalyst, good stability, and a low half-life temperature.

[0026] Preferably, the catalytic radical polymerization is carried out in organic solvent I, and the organic solvent I includes one or more of 1,4-dioxane (DO), tetrahydrofuran, dimethyl sulfoxide, N,N-dimethylformamide, or N,N-dimethylacetamide, and is further preferably 1,4-dioxane (DO). DO as a solvent has a better promoting effect on the polymerization reaction and improves the polymerization efficiency.

[0027] More preferably, the mass ratio of the organic solvent I to 4-acetoxystyrene is 1.5-6:1.

[0028] Preferably, the hydrolysis is carried out by hydrolyzing the product of the catalytic radical polymerization and ammonia water in organic solvent I, and the hydrolysis is milder and does not destroy the structures of other monomers during the reaction process.

[0029] More preferably, the molar ratio of the ammonia water to 4-acetoxystyrene is 1.7-4.2:1, and is further preferably 2-4.2:1.

[0030] Preferably, the temperature of the hydrolysis is 55-90 °C and the time is 5-25 h.

[0031] More preferably, the organic solvent is a mixed solution of propylene glycol methyl ether (PM) and 1,4-dioxane, and the mass ratio of propylene glycol methyl ether to 1,4-dioxane is 1-5:1; the above organic solvent can better improve the yield of precipitation in the subsequent process.

[0032] The mass ratio of the organic solvent to the 4-acetoxystyrene is 1.5 to 6:1.

[0033] Preferably, after hydrolysis, an acid neutralization step is further included; the acid used in the acid neutralization process is glacial acetic acid.

[0034] More preferably, the mass ratio of the glacial acetic acid to the ammonia water is 1.2 to 5:1, and the reaction time for the acid neutralization is 0.5 to 5 h.

[0035] More preferably, the preparation method specifically includes the following steps:

[0036] (1) Add 4-acetoxystyrene, 4-tert-butoxystyrene, tert-butyl methacrylate, a catalyst, and a halogen-containing monomer to organic solvent I, mix evenly, and then heat for reaction to obtain a 4-acetoxystyrene / 4-tert-butoxystyrene / tert-butyl methacrylate / halogen-containing monomer polymer material;

[0037] (2) Precipitate the 4-acetoxystyrene / 4-tert-butoxystyrene / tert-butyl methacrylate / halogen-containing monomer polymer reaction solution in deionized water, dissolve the precipitate in organic solvent II, mix evenly, add ammonia water, and heat for reaction to obtain a 4-p-hydroxystyrene / 4-tert-butoxystyrene / tert-butyl methacrylate / halogen-containing monomer polymer material;

[0038] (3) Add glacial acetic acid to the 4-p-hydroxystyrene / 4-tert-butoxystyrene / tert-butyl methacrylate / halogen-containing monomer polymer material for reaction at room temperature, precipitate in water after the reaction, filter and dry to obtain a halogen-containing high-sensitivity self-acid generating photoresist material.

[0039] A halogen-containing group high-sensitivity self-acid generating photoresist material prepared by the above preparation method.

[0040] Beneficial effects: The photoresist material obtained in the present invention can be directly used for the preparation of a photoresist system, or the solvent can be removed, the powder can be precipitated and then dissolved and formulated.

[0041] A photoresist system, the photoresist system includes the above halogen-containing group high-sensitivity self-acid generating photoresist material;

[0042] Preferably, the photoresist system may further include a photoacid generator, and the mass ratio of the photoacid generator to the halogen-containing group high-sensitivity self-acid generating photoresist material is 0.001 to 0.1:1, and more preferably 0.01 to 0.05:1;

[0043] More preferably, the photoacid generator is a compound that can decompose into a strong acid under the exposure wavelength, which can be ionic and esterified compounds, and can be of the types commonly used in the art, such as sulfonium salts, iodonium salts, etc.; more preferably, the photoacid generator is tert-butylphenyl iodonium perfluorooctanesulfonate, triphenylsulfonium perfluorobutanesulfonate or triphenylsulfonium trifluoromethanesulfonate, HG108, NIT or HG103; the structural formulas of HG108, NIT or HG103 are shown as follows respectively:

[0044]

[0045] Preferably, the photoresist system may further include amine compounds and solvents.

[0046] More preferably, the amine compounds include one or more of tetrabutylammonium hydroxide, triethylamine or triethanolamine, but are not limited to such compounds; preferably, the mass of the amine compounds is 0.1-10% of the mass of the halogen group-containing high-sensitivity self-acid-producing photoresist material.

[0047] More preferably, the solvent can be propylene glycol monomethyl ether acetate, and the mass ratio of the solvent to the halogen group-containing high-sensitivity self-acid-producing photoresist material is specifically adjusted according to the actual film thickness requirements.

[0048] Compared with the prior art, the present invention has the following advantages and technical effects:

[0049] 1. The present invention uses a radical polymerization method to prepare a high-sensitivity PHS series of photoresist resins. By introducing halogen elements (F, Cl, Br) with high EUV absorption ability into the photoresist resin, specifically including hexafluoroisopropanol (HFIP) groups, aliphatic F-containing side chain groups and halogenated benzene ring groups, the lithography performance of the resin is significantly improved. Compared with the photoresist resin without halogen element side groups (the best sensitivity is 50 μC / cm 2 ), the sensitivity of the photoresist resin containing HFIP groups can reach up to 3 μC / cm 2 , almost reaching the minimum exposure dose of an electron beam lithography device. Under the same photoacid generator (PAG) and additive conditions, the resin realizes the best precise exposure and pattern transfer of non-deformed patterns at a 40-nm line width. The sensitivity is about 10 times higher than that of a commercial photoacid generator system, showing the characteristics of high sensitivity and high resolution, and having broad application prospects in the fields of electron beam and EUV lithography processes and semiconductor integrated circuit lithography.

[0050] 2. Thanks to the conjugated stabilization of the aromatic ring and the formation of a dense carbonized layer, the high-sensitivity self-acid-generating lithography material containing halogen groups provided by the present invention exhibits excellent etching resistance and can achieve fine control of the etching rate through molecular design. While improving the energy utilization efficiency and resolution, this material optimizes the chemical reaction characteristics, reduces subsequent etching defects, and provides strong material support for the next-generation lithography technology.

[0051] 3. By introducing various halogen-containing monomer structures into the high-sensitivity self-acid-generating lithography material containing halogen groups of the present invention, it is found that hexafluoroisopropanol (HFIP) has strong electrophilicity and the electron-withdrawing effect of fluorine atoms. The addition of HFIP groups and halogens significantly increases the acidity of the photoresist after exposure, thus achieving imaging without the need for traditional photoacid generators (PAGs). By introducing monomer structures containing halogen elements (F, Cl, Br) with high EUV absorption into the PHS polymer resin, the synthesized resin also has the characteristics of self-acid generation and high-sensitivity lithography ability. Different from the traditional lithography imaging strategy that relies on adding traditional photoacid agents to initiate photochemical reactions, this work uses resin monomers as photosensitive groups and combines them with traditional photoacid agents to carry out photochemical reactions synergistically, reducing the dependence on a single traditional photoacid agent, improving the photoacid generation efficiency, and avoiding the problem that traditional photoacid agents cannot further decompose photochemically when the acid generation efficiency is poor, providing a new research perspective for the high-EUV element lithography absorption mechanism in photoresists.

[0052] 4. The high-sensitivity self-acid-generating lithography material containing halogen groups of the present invention can also be used as a PAG for chemically amplified photoresists, which not only enriches the types of PAGs but also provides inspiration for the rational design of the next-generation photoresists. It provides a new synthetic route for developing EUV materials with better performance. The research results of the present invention further explore the mechanism of halogen-containing photoresists and similar lithography application systems, promote the in-depth understanding of the acid generation and sensitivity change mechanisms in electron beam and EUV exposures, and point out a new direction for advancing the key research on halogen-containing lithography materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The drawings constituting a part of this application are used to provide a further understanding of this application. The schematic embodiments and descriptions thereof of this application are used to explain this application and do not constitute an improper limitation of this application. In the drawings:

[0054] Figure 1 It is a SEM image of a thin film prepared by adding a photoacid generator to the high-sensitivity self-acid-generating lithography material containing halogen groups prepared in Example 1 under electron beam exposure;

[0055] Figure 2 It is a SEM image of a thin film prepared by not adding a photoacid generator to the high-sensitivity self-acid-generating lithography material containing halogen groups prepared in Comparative Example 1 under electron beam exposure;

[0056] Figure 3 SEM image of the film prepared by using the high-sensitivity self-acid-generating lithography material containing halogen groups prepared in Comparative Example 2 without adding a photoacid generator under electron beam exposure. Detailed implementation manners

[0057] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0058] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific implementation manners.

[0059] Unless otherwise specified, the raw materials in the embodiments of the present invention are obtained through commercial channels.

[0060] Unless otherwise specified, the room temperature or normal temperature in the embodiments of the present invention refers to 25 ± 3°C.

[0061] Example 1

[0062] A preparation method of a high-sensitivity self-acid-generating lithography material containing halogen groups, comprising the following steps:

[0063] (1) Preparation of 4-acetoxystyrene / 4-tert-butoxystyrene / tert-butyl methacrylate / halogen-containing monomer polymer material

[0064] Weigh 120.6 g of DO solvent into a round-bottom flask, add 0.2 g of AIBN and mix evenly, then add 21.4 g (132 mmol) of PACS, 5.3 g (37 mmol) of TBMA, 4.8 g of PTBS (27 mmol), and 0.6 g (1.28 mmol) of 3,5-bis(hexafluoroisopropanol)cyclohexyl methacrylate and mix evenly. Then, heat to 80°C and perform magnetic stirring at a rotation speed of 30 rpm / min in a nitrogen environment, and heat and react at 80°C for 6 h. After the reaction is completed, add water for precipitation at a mass ratio of 1:10, and finally filter and dry to obtain 4-acetoxystyrene / 4-tert-butoxystyrene / tert-butyl methacrylate / halogen-containing monomer polymer material.

[0065] (2) Preparation of high-sensitivity self-acid-generating lithography material containing halogen groups

[0066] 120 g of a DO and PM mixed solvent (mass ratio of DO to PM is 1:1) was added to the 4-acetoxystyrene / 4-tert-butoxystyrene / tert-butyl methacrylate / halogen-containing monomer polymer material obtained in step (1) for dissolution. After mixing evenly, 66 g of ammonia water was added and stirred. The reaction was carried out by heating at 80 °C for 5 h. After the hydrolysis was completed, the temperature was lowered to room temperature, and 132 g of HAc was added for neutralization and stirring for 2 h. Then, water was added at a mass ratio of 1:10 for precipitation, and finally, it was filtered and dried to obtain a halogen-containing group high-sensitivity self-acid generating lithography material.

[0067] Example 2

[0068] A preparation method of a halogen-containing group high-sensitivity self-acid generating lithography material, comprising the following steps:

[0069] (1) Preparation of 4-acetoxystyrene / 4-tert-butoxystyrene / tert-butyl methacrylate / halogen-containing monomer polymer material

[0070] 121.3 g of DO solvent was weighed into a round-bottomed flask, 0.2 g of AIBN was added and mixed evenly. Then, 21.4 g of PACS, 5.3 g of TBMA, 4.8 g of PTBS and 0.6 g (2.1 mmol) of A,A-bis(trifluoromethyl)-4-vinylbenzyl alcohol were added and mixed evenly. The temperature was raised to 80 °C, and magnetic stirring was carried out at a speed of 30 rpm / min in a nitrogen atmosphere, and the reaction was carried out by heating at 80 °C for 6 h. After the reaction was completed, water was added at a mass ratio of 1:10 for precipitation, and finally, it was filtered and dried to obtain 4-acetoxystyrene / 4-tert-butoxystyrene / tert-butyl methacrylate / halogen-containing monomer polymer material.

[0071] (2) Preparation of halogen-containing group high-sensitivity self-acid generating lithography material

[0072] 121 g of a DO and PM mixed solvent (mass ratio of DO to PM is 1:1) was added to the 4-acetoxystyrene / 4-tert-butoxystyrene / tert-butyl methacrylate / halogen-containing monomer polymer material obtained in step (1) for dissolution. After mixing evenly, 68 g of ammonia water was added and stirred. The reaction was carried out by heating at 80 °C for 5 h. After the hydrolysis was completed, the temperature was lowered to room temperature, and 136 g of HAc was added for neutralization and stirring for 2 h. Then, water was added at a mass ratio of 1:10 for precipitation, and finally, it was filtered and dried to obtain a halogen-containing group high-sensitivity self-acid generating lithography material.

[0073] Example 3

[0074] A preparation method of a halogen-containing group high-sensitivity self-acid generating lithography material, comprising the following steps:

[0075] (1) Preparation of 4-acetoxystyrene / 4-tert-butoxystyrene / tert-butyl methacrylate / halogen-containing monomer polymer material

[0076] Weigh 120.2 g of DO solvent into a round-bottom flask, add 0.2 g of AIBN (azobisisobutyronitrile) and mix evenly. Then add 21.4 g of PACS, 5.3 g of TBMA, 4.8 g of PTBS and 0.5 g (3.61 mmol) of 4-chlorostyrene and mix evenly. Heat up to 80 °C, and carry out magnetic stirring in a nitrogen environment at a speed of 30 rpm / min, and heat and react at 80 °C for 6 h. After the reaction is completed, add water for precipitation at a mass ratio of 1:10, and finally filter and dry to obtain 4-acetoxystyrene / 4-tert-butoxystyrene / tert-butyl methacrylate / halogen-containing monomer polymer material.

[0077] (2) Preparation of high-sensitivity self-acid-generating lithography material containing halogen groups

[0078] Add 120 g of DO and PM mixed solvent (the mass ratio of DO to PM is 1:1.5) to the 4-acetoxystyrene / 4-tert-butoxystyrene / tert-butyl methacrylate / halogen-containing monomer polymer material obtained in step (1) for dissolution. After mixing evenly, add 65 g of ammonia water and mix and stir, and heat and react at 80 °C for 5 h. After hydrolysis, cool to room temperature, add 130 g of HAc and neutralize and stir for 2 h. Then add water for precipitation at a mass ratio of 1:10, and finally filter and dry to obtain high-sensitivity self-acid-generating lithography material containing halogen groups.

[0079] Comparative Example 1

[0080] A preparation method of a photoresist material, which is different from Example 1 only in that: in step (1), 3,5-bis(hexafluoroisopropanol) cyclohexyl methacrylate is replaced with trifluoroethyl methacrylate of equal molar mass. Other process steps and parameters are the same as those in Example 1.

[0081] Comparative Example 2

[0082] A preparation method of a photoresist material, which is different from Example 1 only in that: in step (1), 3,5-bis(hexafluoroisopropanol) cyclohexyl methacrylate is not added. Other process steps and parameters are the same as those in Example 1.

[0083] Comparative Example 3

[0084] A preparation method of a photoresist material, which is different from Example 1 only in that: step (2) is not included. Other process steps and parameters are the same as those in Example 1.

[0085] Comparative Example 4

[0086] A method for preparing a photoresist material, which is different from Example 1 only in that: the neutralization step of glacial acetic acid is not included in step (2), that is:

[0087] (2) Preparation of a high-sensitivity self-acid-generating photoresist material containing halogen groups

[0088] 120 g of a DO and PM mixed solvent (the mass ratio of DO to PM is 1:1) was added to the 4-acetoxystyrene / 4-tert-butoxystyrene / tert-butyl methacrylate / halogen-containing monomer polymer material obtained in step (1) for dissolution. After mixing evenly, 66 g of ammonia water was added and stirred, and the reaction was carried out at 80 °C for 5 h. After the hydrolysis was completed, the temperature was lowered to room temperature, and then water was added at a mass ratio of 1:10 for precipitation. Finally, it was filtered and dried by suction to obtain a high-sensitivity self-acid-generating photoresist material containing halogen groups.

[0089] All other process steps and parameters are the same as those in Example 1.

[0090] Technical effects:

[0091] The photoresist materials of Examples 1-3 and Comparative Examples 1-2 were subjected to performance tests, and their imaging capabilities were tested using an ultraviolet light and electron beam exposure system. The test results are shown in Table 1. The photolithography performance test was carried out according to the following process conditions, specifically as follows:

[0092] After mixing the photoresist material with propylene glycol methyl ether acetate to obtain a dispersion with a solid content of 5 wt%, the solution was filtered through a 0.2 μm filter. Subsequently, it was sprayed on a silicon substrate by static spraying. After spraying, the rotation speed was set to 300 rpm and rotated for 3 s so that the glue could cover the entire wafer. The rotation speed was increased to 500 rpm and maintained for 5 s, then accelerated to 1200 rpm and maintained for 60 s, and finally decelerated to 300 rpm for 10 s to complete spraying. After coating, it was baked on a hot plate at 120 °C for 2 min. It was exposed by ultraviolet and electron beams respectively. After exposure, it was baked on a hot plate at 130 °C for 2 min. After cooling, it was developed with a 2.38% aqueous solution of tetramethylammonium hydroxide (TMAH) for 90 seconds, and finally rinsed with deionized water for 10 s and spun dry. The exposure imaging test results are shown in Table 1:

[0093] Table 1

[0094]

[0095]

[0096] From the test results of Comparative Examples 1-2 and Examples 1-3, it can be seen that Comparative Examples 1-2 do not have imaging capabilities under ultraviolet and electron beam exposure, while Examples 1-3 have imaging capabilities under ultraviolet and electron beam exposure.

[0097] The thin films prepared from the photoresist materials of Example 1 and Comparative Examples 1-2 were subjected to performance testing using a scanning electron microscope, and the results are as Figures 1-3 shown. It can be seen that the thin films prepared from the high-sensitivity self-acid-generating photoresist material containing halogen groups of the present invention have clear resolution, good film-forming properties, uniform coating distribution under the test of a scanning electron microscope, and excellent optical properties under electron beam exposure conditions. Compared with the thin films prepared from the photoresist materials of Comparative Examples 1-2, Example 1 significantly has higher resolution and better pattern imaging performance.

[0098] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present application should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A preparation method of a highly sensitive self - acid - generating lithography material containing halogen groups, characterized in that, Using 4-acetoxystyrene, 4-tert-butoxystyrene, tert-butyl methacrylate and a halogen-containing monomer as raw materials, and through catalytic radical polymerization followed by hydrolysis, the high-sensitivity self-acid-generating lithography material containing a halogen group is obtained.

2. The preparation method of a highly sensitive self - acid - generating lithography material containing halogen groups according to claim 1, characterized in that, The molar ratio of the 4-acetoxystyrene, 4-tert-butoxystyrene, tert-butyl methacrylate and the halogen-containing monomer is 1:(0.06 - 0.36):(0.06 - 0.29):(0.0097 - 0.28).

3. The preparation method of a highly sensitive self - acid - generating lithography material containing halogen groups according to claim 2, characterized in that, The halogen-containing monomer includes one or more of a monomer containing a hexafluoroisopropanol group, a halogenated styrene monomer and a chloroethyl vinyl ether monomer.

4. The preparation method of a highly sensitive self - acid - generating lithography material containing halogen groups according to claim 1, characterized in that, The temperature of the catalytic radical polymerization is 55 - 90 °C, and the time is 6 - 20 h.

5. The preparation method of a highly sensitive self - acid - generating lithography material containing halogen groups according to claim 4, characterized in that, During the process of the catalytic radical polymerization, the catalyst used is azobisisobutyronitrile or azobisisoheptonitrile; and / or, The mass ratio of the catalyst to the 4-acetoxystyrene is (0.009 - 0.10):

1.

6. The preparation method of a highly sensitive self - acid - generating lithography material containing halogen groups according to claim 1, characterized in that, The hydrolysis is the hydrolysis of the product of the catalytic radical polymerization and ammonia water in an organic solvent.

7. The preparation method of a highly sensitive self - acid - generating lithography material containing halogen groups according to claim 6, characterized in that, The temperature of the hydrolysis is 55 - 90 °C, and the time is 5 - 25 h.

8. The preparation method of a highly sensitive self - acid - generating lithography material containing halogen groups according to claim 1, wherein, After the hydrolysis, it further includes an acid neutralization step; The acid used during the acid neutralization is glacial acetic acid.

9. A high-sensitivity self-acid-generating lithography material containing a halogen group prepared by the preparation method according to any one of claims 1 - 8.

10. A photoresist system, characterized in that, Including the high-sensitivity self-acid-generating lithography material containing a halogen group according to claim 9.

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