A photoresist composition containing a topcoat layer, and a method of making and using the same

Abstract

The present application provides a photoresist composition with top coating, and its preparation method and application. The adamantane structure is introduced into the top coating resin for the first time, and the self-separation top coating photoresist composition with the adamantane structure can simplify the photoetching process, and can accurately form a pattern without additional top coating. The self-separation top coating photoresist composition can improve the contact angle of the upper surface of the photoresist before development, reduce the leaching of the photoresist components and the influence of moisture on the photoresist, has good alkali solubility, and reduces the negative influence on the photoetching pattern.

Description

Technical Field

[0001] This invention belongs to the field of photolithography technology, specifically relating to a photoresist composition with a top coating, its preparation method, and its application. Background Technology

[0002] In ArF immersion lithography, direct contact between the immersion liquid and the photoresist can cause photoresist components to seep into the immersion liquid. This seepage can contaminate optical lenses and may alter the effective refractive index and transmission characteristics of the immersion liquid. To mitigate this issue, scientists have proposed using a top coating on the photoresist as a barrier layer between the immersion liquid and the underlying photoresist. However, using a top coating in immersion lithography presents various challenges. Top coatings, such as their refractive index, thickness, and acidity, interact chemically with the photoresist and influence immersion time, and can affect the photoresist's process window, critical dimension (CD) variation, and profile. Furthermore, some top coatings can cause microbridging defects in the photoresist patterning, negatively impacting device yield.

[0003] For example, in the paper "Self-segregating Materials for Immersion Lithography" by Daniel P. Sanders et al. in Advanced Photoresist Materials and Processing Techniques XXV of the SPIE Proceedings, Volume 6923, pp. 692309-1-692309-12 (2008), to improve the performance of the top coating material, a self-segregating protective coating composition is suggested to form the top coating. Theoretically, a self-segregating top coating would consider a custom material with desired properties at the immersion liquid and photoresist interface, with the key being that the material meets both hydrophobicity and alkali solubility requirements. From a molecular design perspective, this generally involves attaching certain hydrophobic groups to a corresponding polymer material, while simultaneously attaching some acidic groups. With the increasing speed of the immersion lithography exposure platform, higher requirements are placed on the hydrophobicity of the top coating, especially the back-off angle, which needs to be greater than 70°, or even 75°, to avoid water droplets remaining on the silicon wafer due to higher scanning speeds, resulting in watermark defects. Ultimately, as the photoresist components are immersed in the water droplet, the photoresist sensitivity is altered, and water can penetrate the underlying photoresist. Therefore, a top coating with a high back-off angle will allow the immersion exposure machine to operate at higher scan speeds, thereby improving lithography machine capacity utilization. To further increase the scan speed of the lithography machine to improve production volume, the back-off angle of the photoresist top coating needs to be further increased. Summary of the Invention

[0004] This invention provides a self-separating top-coating photoresist composition. This composition simplifies the photolithography process, allowing for precise pattern formation without the need for an additional top coating. The self-separating top-coating photoresist composition improves the contact angle of the photoresist surface before development, reduces the leaching of photoresist components and the impact of moisture on the photoresist, and exhibits good alkali solubility, minimizing negative impacts on the lithographic pattern. Furthermore, the self-separating top-coating photoresist composition can be of both negative and positive types, without particular limitation on the type of photoresist. Moreover, this self-separating top-coating photoresist composition is suitable for ArF immersion lithography processes.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A photoresist composition comprising: a photoresist base resin and a photoresist top coating resin.

[0007] The photoresist top coating resin is a polymer, which is obtained by reacting monomers comprising Formula 1 and / or Formula 2.

[0008] Formula 1 Formula 2

[0009] Among them, R1, R2, R4, R6, R7, and R8 may be the same or different, and are independently selected from H, hydroxyl, carboxyl, and C groups. 1-6 Alkyl, -COOC 1-6 Alkyl, -O-CO-C 1-6 Alkyl, -O-CO-halogenated C 1-6 Alkyl, -O-COOC 1-6 Alkyl, -OC 1-6 Alkyl-OH or -O-COO halogenated C 1-6 alkyl;

[0010] R3 is selected from H or C. 1-6 alkyl.

[0011] According to embodiments of the present invention, R1, R2, R4, R6, R7, and R8 may be the same or different, and are independently selected from H, hydroxyl, carboxyl, and C. 1-3 Alkyl, -COOC 1-3 Alkyl, -O-CO-C 1-3 Alkyl, -O-CO-halogenated C 1-3 Alkyl, -OC 1-3 Alkyl-OH or -O-COOC 1-3 Alkyl group; R3 is selected from H or C 1-3 alkyl.

[0012] In some embodiments of the present invention, the adamantane monomer represented by Formula 1 or Formula 2 is selected from the following structures:

[0013] .

[0014] According to an embodiment of the present invention, the photoresist top coating resin is a polymer comprising the monomers shown in Formula 1 and / or Formula 2 reacted with the monomer shown in Formula III:

[0015] Formula III

[0016] Wherein, R5 is selected from unsubstituted groups, or optionally substituted by one, two or more OH groups, of the following groups: -C 1-6 Alkyl-O-CO-C 1-6 Alkyl-CO-C 1-6 Alkyl, -C 1-6 Alkyl-O-CO-Fluorinated C 1-6 Alkyl, -C 1-6 Alkyl-CO-O-fluorinated C 1-6 Alkyl, -C 1-6 Alkyl-O-CO-C 1-6 Alkyl, -C 1-6 Alkyl-CO-OC 1-6 Alkyl, fluorinated C 1-10 Alkyl, C 1-10 alkyl;

[0017] R 10 Selected from H or C 1-6 alkyl.

[0018] According to an embodiment of the present invention, R5 is selected from unsubstituted or fluorinated C atoms substituted with one OH group. 3-9 Alkyl, C 3-8 Alkyl, -C 1-3 Alkyl-CO-O-fluorinated C 2-4 alkyl.

[0019] According to an embodiment of the present invention, R 10 Selected from H or C 1-3 Alkyl groups, such as H or methyl.

[0020] According to an embodiment of the present invention, the monomer shown in Formula III is, for example, a monomer shown in M6 to M9 as follows:

[0021]

[0022] According to an embodiment of the present invention, the photoresist top coating resin accounts for 1 to 20 wt% of the resin system (photoresist body resin and photoresist top coating resin), for example 1 to 10 wt%, preferably 3 to 7 wt%.

[0023] According to an embodiment of the present invention, the molecular weight of the top coating resin of the photoresist can be 1,000-20,000, preferably 3,000-10,000.

[0024] According to an embodiment of the present invention, the PDI of the top coating resin of the photoresist is 1 to 2, preferably 1.4 to 1.8.

[0025] According to an embodiment of the present invention, the photoresist base resin accounts for 80-99 wt% of the resin system (photoresist base resin and photoresist top coating resin), preferably 92%-97 wt%.

[0026] According to an embodiment of the present invention, the molecular weight of the photoresist host resin can be 1,000-50,000, preferably 4,000-15,000.

[0027] According to an embodiment of the present invention, the photoresist substrate resin is a resin suitable for ArF immersion lithography.

[0028] According to an embodiment of the present invention, the photoresist host resin is, for example, a photoresist resin with a polymethyl methacrylate resin and its derivatives structure, a phenolic resin, or a photoresist resin with a polyhydroxystyrene and its derivatives structure.

[0029] In some embodiments of the present invention, the photoresist host resin is a polymer obtained by reacting at least one of the following monomers:

[0030] .

[0031] In some specific embodiments of the present invention, the photoresist host resin is a copolymer obtained by reacting two or more monomers selected from IPAMA, GBLMA, β-GBLMA, MAMA and MNLOE, for example, a copolymer obtained by reacting three or four monomers.

[0032] According to an embodiment of the present invention, the photoresist composition further comprises additives and solvents.

[0033] According to an embodiment of the present invention, the additive includes an acid generating agent and / or an alkali, and the additive accounts for 0.1 to 30 wt% of the mass of the photoresist main resin, preferably 1 to 28 wt%, and even more preferably 15 to 25 wt%.

[0034] According to embodiments of the present invention, the acid generating agent is selected from photoacid generating agents (PAGs) or thermal acid generating agents (TAGs). Suitable photoacid generating agents are those known in the art for use in chemically amplified photoresists, including, for example: onium salts, such as perfluorobutyltriphenylsulfonium, trifluoromethanesulfonate triphenylsulfonate, trifluoromethanesulfonate (p-tert-butoxyphenyl)diphenylsulfonium, triphenylhydroxythionium, and p-toluenesulfonate triphenylsulfonium; nitrobenzyl derivatives, such as 2-nitrobenzyl-p-toluenesulfonate / ester, 2,6-dinitrobenzyl-p-toluenesulfonate / ester; sulfonates, such as 1,2,3-tris(methanesulfonyloxy)benzene, 1,2,3-tris(trifluoromethanesulfonyloxy)benzene, and 1,2,3-tris(p-toluenesulfonyloxy)benzene; diazomethane derivatives, such as... Examples include bis(benzenesulfonyl)diazomethane and bis(p-toluenesulfonyl)diazomethane; dioxime derivatives, such as bis-O-(p-toluenesulfonyl)-α-dimethyldioxime and bis-O-(n-butanesulfonyl)-α-dimethyldioxime; sulfonate derivatives of N-hydroxyimide compounds, such as N-hydroxysuccinimide methanesulfonate and N-hydroxysuccinimide trifluoromethanesulfonate; and halogen-containing triazine compounds, such as 2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine and 2-(4-methoxynaphthyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, etc.

[0035] Or at least one of PAG1 to PAG3 as shown below:

[0036] PAG1,

[0037] PAG2, PAG3

[0038] According to an embodiment of the present invention, one or more of the PAG or TAG can be added to the photoresist composition, and the specific type and proportion of the added material should be added according to the photolithography process requirements of the photoresist.

[0039] According to an embodiment of the present invention, the acid generating agent accounts for 1 to 25 wt% of the mass of the photoresist main resin, preferably 5 to 20 wt%.

[0040] According to an embodiment of the present invention, the base is selected from at least one of trioctylamine, triethylamine, triethanolamine, N-Boc-4-hydroxypiperidine, tris[2-(2-methoxyethoxy)ethyl]amine, and 2-phenylbenzimidazole.

[0041] According to an embodiment of the present invention, one or more of the alkalis can be added to the photoresist composition for use. Generally, the alkali is present in the photoresist in a small amount, accounting for 0 to 10% of the mass of the photoresist main resin, preferably 0.1 to 5 wt%, such as 0.5 to 3 wt% or 1 to 2.5 wt%.

[0042] According to embodiments of the present invention, the solvent comprises: glycol ethers, such as 2-methoxyethyl ether (diethylene glycol dimethyl ether), ethylene glycol monomethyl ether, and propylene glycol monomethyl ether; propylene glycol monomethyl ether acetate; lactate esters, such as methyl lactate and ethyl lactate; propionate esters, such as methyl propionate, ethyl propionate, ethoxypropionate, and methyl-2-hydroxyisobutyrate; cellosol esters, such as methyl cellosol acetate; aromatic hydrocarbons, such as toluene and xylene; and ketones, such as acetone, ethyl ketone, cyclohexanone, and 2-heptanone. Mixtures of one, two, three, or more solvents described above are also suitable, and the specific solvent type should be selected based on the solubility of the polymer resin and photoresist additives and the coating characteristics. The solvent is typically present in the composition in an amount of 90-99 wt% based on the total weight of the photoresist composition, more typically 93-98 wt%, the specific percentage depending on the requirements for the photoresist solid content and dissolution rate.

[0043] In the photoresist composition of the present invention, during the formation of a photoresist coating, the top coating resin spontaneously migrates and accumulates on the photoresist surface during the coating / baking process, forming a thin layer. Therefore, the photoresist composition of the present invention can be used as a top coating in a photolithography process, eliminating the need for additional top coatings.

[0044] The present invention also provides a self-separating photoresist top coating resin, which is obtained by polymerization of monomers comprising the monomers shown in Formula 1 and / or Formula 2 as described above. According to an embodiment of the present invention, the photoresist top coating resin is obtained by polymerization of monomers comprising the monomers shown in Formula 1 and / or Formula 2 and the monomer shown in Formula III.

[0045] The present invention also provides a method for preparing the above-mentioned self-separating photoresist top coating resin, comprising the following steps:

[0046] The monomers shown in Formula 1 and / or Formula 2, and optionally the monomers shown in Formula III (e.g., the monomers shown in M6 to M9 as described above), are subjected to polymerization.

[0047] According to an embodiment of the present invention, the preparation method of the top coating resin includes: adding resin monomers, initiators, optionally molecular weight regulators, and solvents in appropriate proportions to a container equipped with a stirrer, a reflux condenser, and a constant pressure titrator under a nitrogen atmosphere; and stirring and reacting at a constant temperature of 50~80°C for 1~48 hours.

[0048] According to an embodiment of the present invention, after the reaction is completed, the obtained top coating resin product is precipitated in pure water, washed with pure water, and after precipitation and filtration, a solid product is obtained and dried in a vacuum oven.

[0049] According to an embodiment of the present invention, the photoresist top coating resin synthesis process uses an initiator and optionally a molecular weight regulator, the proportions of which are 0.1-10% of the total molar number of the top coating resin monomers, preferably 1-10%. The actual proportion should be added according to the requirements for the molecular weight and distribution of the top coating resin. Commonly used initiators include azo initiators such as azobisisobutyronitrile (AIBN), azobisisoheptanenitrile (ABVN), dimethyl azobisisobutyrate (also known as V601, AIBME), azoisobutylcyanoformamide (V30), azobisisobutyramidine hydrochloride (AIBA), azobisisobutyramidoline hydrochloride (AIBI), nDT, etc.; commonly used molecular weight regulators include: dodecyl mercaptan, mercaptoethanol, mercaptoacetic acid, isooctyl 3-mercaptopropionate (IOMP), AMSD, etc.

[0050] The present invention also provides a method for preparing the above-mentioned photoresist composition, comprising the following steps:

[0051] The photoresist base resin and the photoresist top coating resin are mixed.

[0052] According to an embodiment of the present invention, the method for preparing the photoresist composition includes: mixing and dissolving a photoresist base resin, a photoresist top coating resin, optional additives and a solvent system in a weight ratio, filtering and removing metals to prepare the photoresist composition.

[0053] The present invention also provides a method for forming photolithographic patterns using the above-mentioned photoresist composition, comprising the following steps:

[0054] The photoresist composition of the present invention is applied onto a substrate;

[0055] The coated photoresist composition is sequentially subjected to pre-baking, exposure, development, and post-baking operations to obtain the corresponding photolithographic pattern of the photoresist composition.

[0056] According to an embodiment of the present invention, the method further includes: first coating a bottom antireflective coating composition onto a substrate, baking and curing it before coating the photoresist composition thereon.

[0057] The present invention also provides the use of the above-described photoresist composition for photolithography, such as ArF lithography, particularly ArF immersion lithography.

[0058] Beneficial effects

[0059] This invention provides a novel self-separating topcoat resin and a photoresist composition containing the topcoat resin. This invention introduces an adamantane structure into the topcoat resin for the first time. The photoresist composition containing the adamantane-structured topcoat resin of this invention simplifies the photolithography process, allowing for precise pattern formation without the need for an additional topcoat. During the coating / baking process, the topcoat resin in the photoresist composition of this invention automatically separates and accumulates on the photoresist surface due to its hydrophobicity and low surface energy, forming a topcoat. Therefore, it eliminates the need for a separate topcoat on top of the photoresist, saving on additional topcoat resin preparation, coating, and baking processes, thus reducing production costs.

[0060] The photoresist composition of the present invention can improve the contact angle of the upper surface of the photoresist before development, reduce the leaching of photoresist components and the influence of moisture on the photoresist, has good alkali solubility, reduces the negative impact on photolithographic patterns, and results in clear patterns and low line width roughness after photolithography.

[0061] Furthermore, the photoresist composition of the present invention is applicable to both negative and positive photoresists, and there is no particular limitation on the type of photoresist. The photoresist composition of the present invention is particularly suitable for ArF immersion lithography processes.

[0062] Terminology Definitions and Explanations

[0063] Unless otherwise defined, all technical terms herein have the same meaning as commonly understood by one of ordinary skill in the art to which the subject matter of the claims pertains.

[0064] The term "halogen" includes F, Cl, Br, or I. "Halogenated" means replaced by F, Cl, Br, or I.

[0065] Term "C" 1-6 "Alkyl" means a straight-chain or branched alkyl group having 1, 2, 3, 4, 5, or 6 carbon atoms. The alkyl group is, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, 2-methylbutyl, 1-methylbutyl, 1-ethylpropyl, 1,2-dimethylpropyl, neopentyl, 1,1-dimethylpropyl, 4-methylpentyl, 3-methylpentyl, 2-methylpentyl, 1-methylpentyl, 2-ethylbutyl, 1-ethylbutyl, 3,3-dimethylbutyl, 2,2-dimethylbutyl, 1,1-dimethylbutyl, 2,3-dimethylbutyl, 1,3-dimethylbutyl, or 1,2-dimethylbutyl, or their isomers.

[0066] The term "halogenated C" 1-6 "alkyl" indicates the above term "C 1-6 At least one H in the alkyl group is replaced by a halide ion. Attached Figure Description

[0067] Figure 1 Photolithography test patterns for photoresists P1, P15, and P17 (the scale bar in the first column is 0.66µm). Detailed Implementation

[0068] The present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0069] Unless otherwise specified, the experimental methods used in the following examples are conventional methods; unless otherwise specified, the reagents and materials used in the following examples are commercially available.

[0070] The monomer structure used in the top coating resin of the photoresist in the following embodiments is shown below:

[0071]

[0072] Synthesis method of top coating resin T1:

[0073] The oil bath temperature was set to 75℃. After the temperature stabilized, a mixed solution of 30 mol% M9 (30% mol means that the molar percentage of M9 monomer in the total monomer M9+M2 is 30%), 70 mol% M2 (70% mol means that the molar percentage of M2 monomer in the total monomer M9+M2 is 70%), 5 mol% V601 (5 mol% means that the molar percentage of V601 in the total monomer M9+M2 is 5%), 5 mol% nDT (5 mol% means that the molar percentage of nDT in the total monomer M9+M2 is 5%), and 210 g of isopropanol was added to a 500 ml three-necked round-bottom flask equipped with a stirrer, reflux condenser, and constant pressure titrator. The reaction was stirred at a constant temperature of 75℃ for 24 h. After the reaction was completed, the product was precipitated in 1000 ml of pure water and washed three times with 500 ml of pure water. After precipitation and filtration, a solid product was obtained and dried in a vacuum oven. The yield was 85%, and the molecular weight and molecular weight distribution of the product were 6300 and 1.55, respectively.

[0074] The synthesis methods of top coating resins T2~T14 and comparative top coating resins T15~T18 are the same as those of top coating resin T1. The resin synthesis components and the proportions of each raw material for top coating resins T1~T14 and comparative examples T15~T18 are shown in Table 1.

[0075] Table 1. Top Coating Resin Examples T1-T14 and Comparative Examples T15-T18: Resin Synthesis Components and Raw Material Proportions

[0076]

[0077] * The molar percentage of the total molar amount of all top-coating resin monomers;

[0078] # The percentage by mass of the solvent relative to all components in the reaction system.

[0079] In the table above, V601 refers to dimethyl azobisisobutyrate (CAS No.: 2589-57-3); nDT refers to n-dodecyl mercaptan (CAS: 112-55-0); and IPA refers to isopropanol.

[0080] In the table above, when a cell is blank, it means that the cell does not contain a certain component.

[0081] As shown in Table 1, the molecular weight of the top coating resin prepared by the synthesis method of the present invention is between 3,000 and 10,000, and the molecular weight distribution is between 1.4 and 1.8. If there are special requirements for the molecular weight and distribution of the top coating resin, they can be achieved by adjusting the proportion and type of initiator and / or molecular weight regulator. For example, the molecular weight and distribution of the top coating resins T1, T3, and T11 can be adjusted by changing the proportion of initiator and molecular weight regulator.

[0082] Preparation of photoresist P1:

[0083] The main resin (R1, 3.449 wt%), top coating resin T1 (0.172 wt%), photoacid generator (PAG1, 0.103 wt%; PAG2, 0.483 wt%), alkali (2-phenylbenzimidazole, 0.062 wt%), and solvent (PGMEA / CHO, 95.731 wt%) were mixed, dissolved, and filtered to obtain the photoresist (stored away from light).

[0084] The preparation methods of photoresists P2~P12 and comparative photoresists P13~P16 are the same as those of photoresist P1. The component proportions of photoresists P1~P12 and comparative photoresists P13~P16 are shown in Table 2.

[0085] Preparation of comparative photoresist P17:

[0086] The main resin (R1, 3.449 wt%), photoacid generator (PAG1, 0.103 wt%; PAG2, 0.483 wt%), alkali (2-phenylbenzimidazole, 0.062 wt%), and solvent (PGMEA / CHO, 95.903 wt%) were mixed, dissolved, and filtered to obtain the photoresist (stored away from light).

[0087] Table 2. Components and proportions of photoresist P1~P17

[0088]

[0089] In the table above, T1:T9=1:1 means that top coating resins T1 and T9 are added to the photoresist system at a mass ratio of 1:1. Similarly, the proportions in this column all refer to the addition of two different top coating resins to the photoresist system at different mass ratios.

[0090] PGMEA / CHO=7:3 means that the solvents PGMEA (propylene glycol methyl ether acetate) and CHO (cyclohexanone) are added to the photoresist system in a mass ratio of 7:3. Similarly, the ratios in this column all refer to the addition of two different solvents to the photoresist system in different mass ratios.

[0091] In the table above, the main resin (R1, 3.449Wt%) refers to the mass fraction of the main resin relative to the total mass of the main resin, top coating resin T1, photoacid generator, alkali, and solvent, which is 3.449Wt%. Similarly, the Wt% values ​​for each substance in Table 2 have the same meaning.

[0092] In the table above, when a cell is blank, it means that the cell does not contain a certain component.

[0093] The photoresist base resins R1~R4 were produced by Guoke Tianji (Shandong) New Materials Co., Ltd., and their structure and synthesis method are as follows:

[0094]

[0095] Synthesis method of photoresist base resin R1:

[0096] The oil bath temperature was set to 70℃. After the temperature stabilized, a mixed solution of 10 mol% IPAMA (10 mol% means IPAMA accounts for 10% of the total molar amount of resin monomers), 30 mol% GBLMA (30 mol% means GBLMA accounts for 30% of the total molar amount of resin monomers), 51 mol% MAMA (51 mol% means MAMA accounts for 51% of the total molar amount of resin monomers), 9 mol% MNLOE (9 mol% means MNLOE accounts for 9% of the total molar amount of resin monomers), 2 mol% V601 (2 mol% means V601 accounts for 2% of the total molar amount of monomers), 2 mol% nDT (2 mol% means nDT accounts for 2% of the total molar amount of monomers), and 400 g PGMEA was added to a 1000 ml three-necked round-bottom flask equipped with a stirrer, reflux condenser, and constant pressure titrator. The reaction was stirred at a constant temperature of 70℃ for 24 h. After the reaction was completed, the product was precipitated in 1000 ml of n-hexane and washed three times with 500 ml of pure water. After precipitation and filtration, a solid product was obtained and dried in a vacuum oven. The yield was 85%, and the molecular weight and molecular weight distribution of the product were 8290 / 1.70, respectively.

[0097] Synthesis method of photoresist base resin R2:

[0098] The oil bath temperature was set to 70℃. After the temperature stabilized, a mixed solution of 10 mol% IPAMA (10 mol% means IPAMA accounts for 10% of the total molar amount of resin monomers), 30 mol% β-GBLMA (30 mol% means β-GBLMA accounts for 30% of the total molar amount of resin monomers), 51 mol% MAMA (51 mol% means MAMA accounts for 51% of the total molar amount of resin monomers), 9 mol% MNLOE (9 mol% means MNLOE accounts for 9% of the total molar amount of resin monomers), 2 mol% V601 (2 mol% means V601 accounts for 2% of the total molar amount of monomers), 2 mol% nDT (2 mol% means nDT accounts for 2% of the total molar amount of monomers), and 400 g PGMEA was added to a 1000 ml three-necked round-bottom flask equipped with a stirrer, reflux condenser, and constant pressure titrator. The reaction was stirred at a constant temperature of 70℃ for 24 h. After the reaction was completed, the product was precipitated in 1000 ml of n-hexane and washed three times with 500 ml of pure water. After precipitation and filtration, a solid product was obtained and dried in a vacuum oven. The yield was 87%, and the molecular weight and molecular weight distribution of the product were 9200 / 1.69, respectively.

[0099] Synthesis method of photoresist base resin R3:

[0100] The oil bath temperature was set to 70℃. After the temperature stabilized, a mixed solution of 30 mol% IPAMA, 10 mol% GBLMA, 51 mol% MAMA, 9 mol% MNLOE, 2 mol% V601, 2 mol% nDT, and 400 g PGMEA was added to a 1000 ml three-necked round-bottom flask equipped with a stirrer, reflux condenser, and constant-pressure titrator under a nitrogen atmosphere. The reaction was stirred at 70℃ for 24 h. After the reaction was completed, the product was precipitated in 1000 ml of n-hexane and washed three times with 500 ml of pure water. The solid product was obtained by precipitation and filtration, and then dried in a vacuum oven. The yield was 90%, and the molecular weight and molecular weight distribution of the product were 8500 / 1.67, respectively.

[0101] Synthesis method of photoresist base resin R4:

[0102] The oil bath temperature was set to 70℃. After the temperature stabilized, a mixed solution of 40 mol% IPAMA, 51 mol% MAMA, 9 mol% MNLOE, 2 mol% V601, 2 mol% nDT, and 400 g PGMEA was added to a 1000 ml three-necked round-bottom flask equipped with a stirrer, reflux condenser, and constant-pressure titrator under nitrogen atmosphere. The reaction was stirred at 70℃ for 24 h. After the reaction was completed, the product was precipitated in 1000 ml of n-hexane and washed three times with 500 ml of pure water. After precipitation and filtration, a solid product was obtained and dried in a vacuum oven. The yield was 84%, and the molecular weight and molecular weight distribution of the product were 9500 / 1.74, respectively.

[0103] The photoacids PAG1~PAG3 are produced by Guoke Tianji (Shandong) New Materials Co., Ltd., and their structures are shown below:

[0104] PAG1,

[0105] PAG2, PAG3

[0106] Photoresist top coating performance test:

[0107] Contact angle test: Photoresist P1~P17 prepared as described above was spin-coated onto a 4-inch clean silicon wafer at 1500 rpm, and then pre-baked for 60 s (at 100 ℃). The static angle of a 5 μL pure water droplet on the photoresist surface and the rolling angle of a 50 μL pure water droplet on the photoresist surface were measured using an optical contact angle tension meter. The contact angle data of photoresist P1-P17 are shown in Table 3.

[0108] Table 3. Contact angle test data of photoresist P1~P17

[0109]

[0110] As shown in Table 3, comparing the data of P1 / P13 / P14, P3 / P15, and P4 / P16 in the same formulation, it can be seen that the photoresist with the photoresist top coating resin described in this invention and the photoresist with a non-photoresist top coating resin described in this invention have similar or even higher contact angles (CA) and (RCA) before development, and similar or even lower (SA) before development. Comparing the data of P1 / P17 in the same formulation, it can be seen that compared with photoresist P17 without the photoresist top coating resin, the CA (static angle) and RCA (receding angle) before development are higher, and the SA (roll-off angle) is lower. In immersion lithography, the receding contact angle (RCA) between the top coating and water must be greater than 70°, and the SA before development should be sufficiently small. This is to ensure that the silicon wafer platform can move quickly under the water-containing exposure head during exposure, without leaving water droplets. The test results above show that photoresists P1~P12 with the photoresist top coating resin described in this invention exhibit good contact angle performance.

[0111] 2) Dissolution rate test: Prepare a 20% solid content sample of photoresist top coating resin T1~T18 (solvent is PGMEA). Spin-coat the 20% sample of photoresist top coating resin T1~T18 onto a 4-inch clean silicon wafer at 1500 rpm. Then perform a pre-baking operation for 60s (at 100℃). Develop with 25% TMAH (tetramethylammonium hydroxide) for 10s. Test the film thickness before and after development.

[0112] Table 4. Dissolution rate test of top coating resins T1~T18

[0113]

[0114] As shown in Table 4, compared with T15-T17 (with non-photoresist top coating resins) and T18 (without top coating resins), the photoresist top coating resins T1-T14 of the present invention have a faster dissolution rate in 25% TMAH solution and a thinner film thickness after development.

[0115] 3) Leaching test: Photoresist P1~P17 was spin-coated onto a 4-inch clean silicon wafer at 1500 rpm, and then pre-baked for 60 seconds (at 100°C). The photoacid cations in the leaching solution were detected using an immersion leaching analyzer to test the ability of the top coating resin to prevent leaching in the photoresist.

[0116] Table 5. Leaching and photolithography test data for photoresists P1~P17

[0117]

[0118] As shown in Table 5, in the same formulation, comparing the data of P1 / P13 / P14, P3 / P15 and P4 / P16, it can be seen that the photoresist with the photoresist top coating resin described in this invention has a similar or even stronger ability to prevent leaching compared to the photoresist with a photoresist top coating resin other than that described in this invention. In the same formulation, comparing the data of P1 / P17, it can be seen that the photoresist P1 with the photoresist top coating resin described in this invention has a much higher ability to prevent leaching than the photoresist P17 without the photoresist top coating resin.

[0119] 4) Photolithography performance test: Photoresist P1~P17 was spin-coated onto a clean silicon wafer at 1500 rpm. A pre-bake operation of 60 s (at 100℃) was performed to form a 90 nm photoresist film. Exposure was performed simultaneously using an ArF immersion lithography machine. Then, development was performed with 2.38 Wt% tetramethylammonium hydroxide for 60 s, followed by a post-bake of 60 s (at 100℃) to obtain the desired pattern. The top morphology and LWR of the pattern were observed using a scanning electron microscope, and the energy window was measured simultaneously. The results are shown in Table 5.

[0120] A) In the same formulation, comparing the data of P1 / P13 / P14, P3 / P15 and P4 / P16, it can be seen that the photoresist with the photoresist top coating resin described in this invention has basically the same critical dimension CD at the same exposure energy as the photoresist with the photoresist top coating resin not described in this invention; In the same formulation, comparing the data of P1 / P17, it can be seen that the photoresist P1 with the photoresist top coating resin described in this invention has a lower critical dimension CD at the same exposure energy compared with the photoresist P17 without the photoresist top coating resin.

[0121] B) In the same formulation, comparing the data of P1 / P13 / P14, P3 / P15 and P4 / P16, it can be seen that: the photoresist with the photoresist top coating resin described in this invention has a larger energy window and the optimal exposure energy is basically the same or lower than that of the photoresist with a photoresist top coating resin other than that described in this invention; in the same formulation, comparing the data of P1 / P17, it can be seen that: compared with the photoresist P17 without the photoresist top coating resin, the photoresist P1 with the photoresist top coating resin described in this invention has a larger energy window and the optimal exposure energy required to achieve the required size is lower.

[0122] C) In the same formulation, comparing the data of P1 / P13 / P14, P3 / P15 and P4 / P16, it can be seen that the photoresist with the photoresist top coating resin described in this invention has a smaller linewidth roughness (LWR) than the photoresist P13~P16 with a top coating resin other than that described in this invention; in the same formulation, comparing the data of P1 / P17, it can be seen that the photoresist P1 with the photoresist top coating resin described in this invention has a smaller linewidth roughness than the photoresist P17 without the top coating resin.

[0123] D) Comparing the data of P1 / P13 / P14, P3 / P15, and P4 / P16 in the same formulation, it can be seen that the photoresist with the top coating resin of the present invention has no microbridge structure, while the photoresist P15 with a top coating resin other than that described in the present invention and the photoresist P17 without a top coating resin have microbridge structures. The photolithography results are as follows: Figure 1 As shown.

[0124] The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A photoresist composition comprising: Photoresist base resin and photoresist top coating resin The photoresist top coating resin is a polymer, which is obtained by reacting monomers comprising Formula 1 and / or Formula 2. Formula 1 Formula 2 Among them, R1, R2, R4, R6, R7, and R8 may be the same or different, and are independently selected from H, hydroxyl, carboxyl, and C groups. 1-3 Alkyl, -COOC 1-3 Alkyl, -O-CO-C 1-3 Alkyl, -O-CO-halogenated C 1-3 Alkyl, -O-COOC 1-3 Alkyl, -OC 1-3 Alkyl-OH or -O-COO halogenated C 1-3 alkyl; R3 is selected from H or C. 1-3 alkyl; The photoresist host resin is a polymer obtained by reacting at least one of the following monomers: 。 2. The photoresist composition according to claim 1, wherein, The photoresist top coating resin is a polymer obtained by reacting monomers of Formula 1 and / or Formula 2 with monomers of Formula III: Formula III Wherein, R5 is selected from unsubstituted groups, or optionally substituted by one, two or more OH groups, of the following groups: -C 1-6 Alkyl-O-CO-C 1-6 Alkyl-CO-C 1-6 Alkyl, -C 1-6 Alkyl-O-CO-fluorinated C 1-6 Alkyl, -C 1-6 Alkyl-CO-O-fluorinated C 1-6 Alkyl, -C 1-6 Alkyl-O-CO-C 1-6 Alkyl, -C 1-6 Alkyl-CO-OC 1-6 Alkyl, fluorinated C 1-10 Alkyl, C 1-10 alkyl; R 10 Selected from H or C 1-6 alkyl.

3. The photoresist composition according to claim 2, wherein, R5 is selected from unsubstituted fluorinated C atoms that have been substituted with an OH group. 3-9 Alkyl, C 3-8 Alkyl, -C 1-3 Alkyl-O-CO-fluorinated C 2-4 alkyl.

4. The photoresist composition according to claim 2, wherein, R 10 Selected from H or C 1-3 alkyl.

5. The photoresist composition according to claim 2, wherein, The monomers shown in Formula III are the monomers shown as M6 to M9 below:

6. The photoresist composition according to claim 1, wherein, The adamantane monomers represented by Formula 1 or Formula 2 are selected from the following structures: CAS:66786-61-6 862286-54-2。 7. The photoresist composition according to any one of claims 1-6, wherein, The top coating resin of the photoresist accounts for 1~20wt% of the resin system.

8. The photoresist composition according to any one of claims 1-6, wherein, The molecular weight of the top coating resin of the photoresist is 1000-20000.

9. The photoresist composition according to any one of claims 1-6, wherein, The PDI of the top coating resin of the photoresist is 1~2.

10. The photoresist composition according to any one of claims 1-6, wherein, The photoresist main resin accounts for 80~99wt% of the polymer resin system.

11. The photoresist composition according to any one of claims 1-6, wherein, The molecular weight of the photoresist base resin is 1000-50000.

12. The photoresist composition according to any one of claims 1-6, wherein, The photoresist composition also contains additives and solvents; The additives include an acid generating agent and an alkali, and the additives account for 0.1 to 30 wt% of the bulk photoresist resin.

13. The photoresist composition according to claim 12, wherein, The acid generator is selected from photoacid generator (PAG) or thermal acid generator (TAG).

14. The photoresist composition according to claim 12, wherein, The alkali accounts for 1 to 20 wt% of the photoresist resin.

15. The photoresist composition according to claim 12, wherein, The base is selected from at least one of trioctylamine, triethylamine, triethanolamine, N-Boc-4-hydroxypiperidine, tris[2-(2-methoxyethoxy)ethyl]amine, and 2-phenylbenzimidazole.

16. A method for preparing the photoresist composition according to any one of claims 1-15, wherein, Includes the following steps: The photoresist base resin and the photoresist top coating resin are mixed.

17. The preparation method according to claim 16, wherein, The method for preparing the photoresist composition includes: mixing and dissolving the photoresist base resin, the photoresist top coating resin, optional additives and solvent system according to the weight ratio, filtering and removing metals to prepare the photoresist composition.

18. A method for forming a photolithographic pattern using the photoresist composition according to any one of claims 1-15, wherein, Includes the following steps: The photoresist composition according to any one of claims 1-15 is applied to a substrate; The coated photoresist composition is sequentially subjected to pre-baking, exposure, development, and post-baking operations to obtain the corresponding photolithographic pattern of the photoresist composition.

19. The method according to claim 18, wherein, The method further includes: before applying the photoresist composition, first applying a bottom anti-reflective coating composition to the substrate, baking and curing it, and then applying the photoresist composition of any one of claims 1-15 thereon.

20. Use of the photoresist composition according to any one of claims 1-15 for ArF immersion lithography.

21. A self-separating photoresist top coating resin, wherein, It is obtained by polymerization of monomers comprising Formula 1 and / or Formula 2: Formula 1 Formula 2 Among them, R1, R2, R4, R6, R7, and R8 may be the same or different, and are independently selected from H, hydroxyl, carboxyl, and C groups. 1-3 Alkyl, -COOC 1-3 Alkyl, -O-CO-C 1-3 Alkyl, -O-CO-halogenated C 1-3 Alkyl, -O-COOC 1-3 Alkyl, -OC 1-3 Alkyl-OH or -O-COO halogenated C 1-3 alkyl; R3 is selected from H or C. 1-3 alkyl.

22. The self-separating photoresist top coating resin according to claim 21, wherein, The photoresist top coating resin is obtained by polymerizing monomers comprising Formula 1 and / or Formula 2 with monomers comprising Formula III: Formula III Wherein, R5 is selected from unsubstituted groups, or optionally substituted by one, two or more OH groups, of the following groups: -C 1-6 Alkyl-O-CO-C 1-6 Alkyl-CO-C 1-6 Alkyl, -C 1-6 Alkyl-O-CO-fluorinated C 1-6 Alkyl, -C 1-6 Alkyl-CO-O-fluorinated C 1-6 Alkyl, -C 1-6 Alkyl-O-CO-C 1-6 Alkyl, -C 1-6 Alkyl-CO-OC 1-6 Alkyl, fluorinated C 1-10 Alkyl, C 1-10 alkyl; R 10 Selected from H or C 1-6 alkyl.

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