Photoresist composition and pattern forming method thereof

Abstract

The invention discloses a photoresist composition. The photoresist composition comprises film-forming resin (A) and a solvent (B), the film-forming resin (A) comprises a first polymer and a second polymer, the first polymer has a structural unit as shown in the following formula (I), and the second polymer has a structural unit as shown in the following formula (II). The photoresist composition is used to form a resist film on a substrate, and the resist film is subjected to high-energy radiation exposure and development to obtain a pattern. According to the invention, the first polymer with the structural unit shown in the formula (I) and the second polymer with the structural unit shown in the formula (II) are used, so that the resist film with relatively good resolution and line width roughness can be obtained. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor photoresists, and more specifically, to a photoresist composition and a method for forming a pattern thereof. Background Art

[0002] Photoresists are photosensitive films used to transfer images to substrates, and they form negative or positive images. After coating the substrate with photoresist, the coating is exposed to a light source such as ultraviolet light through a patterned photomask, and a resist pattern with a predetermined shape is formed on the resist film through a development process.

[0003] Known photoresists can provide features with resolution and size sufficient for many existing commercial applications. However, for many other applications, new photoresists are needed that can provide higher resolution images.

[0004] Currently, resin (acrylic resin) or the like is generally used as a base resin of a resist composition used in ArF excimer laser lithography or the like.

[0005] To meet the challenges of high-resolution lithography on photoresist materials, photoacid generators (PAGs) with low and controllable diffusion properties are required, especially ionic PAGs with photoreactive cations and diffusion-limited anions. In addition, whether the PAG is evenly distributed in the resist film also has a great influence on the overall performance of the photoresist. Summary of the invention

[0006] An object of the present invention is to solve at least the above problems and to provide at least the advantages which will be described hereinafter.

[0007] Another object of the present invention is to provide a photoresist composition, wherein a photoacid generator is combined with a film-forming resin so that its structure can be more evenly distributed in the resist, thereby being more evenly distributed in the resist film, and the resolution of the photoresist can be better controlled; an acid diffusion inhibitor is combined with a film-forming resin so that its structure can be more evenly distributed in the resist, the acid diffusion is more controlled, and the control of line width roughness (LWR) can be better.

[0008] In order to achieve these objects and other advantages according to the present invention, a photoresist composition is provided, comprising a film-forming resin (A) and a solvent (B); the film-forming resin (A) comprises a first polymer and a second polymer, the first polymer having a structural unit represented by the following formula (I), and the second polymer having a structural unit represented by the following formula (II);

[0009]

[0010] In formula (I) and formula (II), R is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; R1 is a hydrogen atom, a halogen atom, a nitro group, an amino group, an alkyl group having 1 to 3 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, an alkyl group having 1 to 3 carbon atoms containing an ether bond, a keto bond or an ester bond, or an alkenyl group having 2 to 4 carbon atoms containing an ether bond, a keto bond or an ester bond; R2 is a hydrogen atom, a halogen atom, a nitro group, an amino group or an alkyl group having 1 to 3 carbon atoms; L is an alkane group having 1 to 6 carbon atoms containing or not containing an ester bond; M is a sulfonic acid group or a carboxyl group; P is a photoactive cation; n and m are each an integer of 1 to 3; a, b, c, d, and e are each between 0.01 and 0.99, a+b+c+d=1, a+b+c+e=1, and a, b, c, d, and e represent the molar proportions.

[0011] Preferably, the first polymer accounts for 60 to 80 wt % of the film-forming resin (A), and the second polymer accounts for 20 to 40 wt % of the film-forming resin (A).

[0012] Preferably, a is between 0.2 and 0.4, b is between 0.3 and 0.5, c is between 0.1 and 0.3, d is between 0.01 and 0.1, and e is between 0.01 and 0.1.

[0013] Preferably, the photoresist composition further comprises a fluorine-containing resin, wherein the fluorine-containing resin has a structural unit represented by the following formula (III):

[0014]

[0015] f and g are respectively between 0.01 and 0.99, f+g=1, and f and g respectively represent the molar proportions.

[0016] Preferably, the fluorine-containing resin accounts for 0.01 to 1 wt % in the photoresist composition.

[0017] Specifically, the first polymer includes one or more of the following structural units:

[0018]

[0019] Specifically, the second polymer includes one or more of the following structural units:

[0020]

[0021] Preferably, the second polymer comprises one or more of the structural units shown below:

[0022]

[0023] Specifically, the mass ratio of the film-forming resin (A) to the solvent (B) is 100:(1000-30000).

[0024] The present invention provides a pattern forming method, which comprises the steps of forming a resist film on a substrate using the photoresist composition, exposing the resist film to high-energy radiation, and developing the resist film to obtain a pattern.

[0025] The present invention has at least the following beneficial effects:

[0026] 1. When the first polymer accounts for 60-80wt% and the second polymer accounts for 20-40wt%, the prepared resist has suitable LWR and resolution;

[0027] 2. Compared with free photoacid generators, binding the photoacid generator to the film-forming resin can make its structure more evenly distributed in the resist, thereby making the distribution in the resist film more uniform and the resolution control of the photoresist better;

[0028] 3. Compared with free acid diffusion inhibitors, binding the acid diffusion inhibitor to the film-forming resin can make its structure more evenly distributed in the resist, the acid diffusion is more controlled, and the control of line width roughness (LWR) is better.

[0029] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. DETAILED DESCRIPTION

[0030] A first aspect of the present invention provides a photoresist composition comprising a film-forming resin (A) and a solvent (B).

[0031] <Film-forming resin (A)>

[0032] In the present invention, the film-forming resin (A) comprises a first polymer and a second polymer, the first polymer having a structural unit represented by the following formula (I), and the second polymer having a structural unit represented by the following formula (II);

[0033]

[0034] In formula (I) and formula (II), R is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; R1 is a hydrogen atom, a halogen atom, a nitro group, an amino group, an alkyl group having 1 to 3 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, an alkyl group having 1 to 3 carbon atoms containing an ether bond, a keto bond or an ester bond, or an alkenyl group having 2 to 4 carbon atoms containing an ether bond, a keto bond or an ester bond; R2 is a hydrogen atom, a halogen atom, a nitro group, an amino group or an alkyl group having 1 to 3 carbon atoms; L is an alkyl group having 1 to 6 carbon atoms containing or not containing an ester bond; M is a sulfonic acid group or a carboxyl group; and P is a photoactive cation.

[0035] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

[0036] Examples of the alkyl group having 1 to 3 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group and cyclopropyl group.

[0037] Examples of the alkenyl group having 2 to 4 carbon atoms include vinyl, 1-propenyl, 2-propenyl, 1-methyl-1-vinyl, 1-butenyl, 2-butenyl, 3-butenyl, 2-methyl-1-propenyl, 2-methyl-2-propenyl, 1-ethylvinyl, 1-methyl-1-propenyl and 1-methyl-2-propenyl.

[0038] Exemplary P + The cation structure can be shown as follows:

[0039]

[0040] In formula (I) and formula (II), n and m are integers of 1 to 3, and n and m can be integers of 1, 2, and 3, respectively; a, b, c, d, and e are integers of 0.01 to 0.99, a+b+c+d=1, a+b+c+e=1, and a, b, c, d, and e represent molar percentages, respectively. a is preferably between 0.2 and 0.4, preferably between 0.25 and 0.4, and most preferably 0.35; b is preferably between 0.3 and 0.5, preferably between 0.35 and 0.45, and most preferably 0.4; c is preferably between 0.1 and 0.3, preferably between 0.15 and 0.25, and most preferably 0.2; d is preferably between 0.01 and 0.1, preferably between 0.03 and 0.08, and most preferably between 0.04 and 0.06; e is preferably between 0.01 and 0.1, preferably between 0.03 and 0.08, and most preferably between 0.04 and 0.06.

[0041] In the present invention, the first polymer represented by formula (I) consists of the following structure;

[0042]

[0043] The first polymer includes one or more of the structural units shown below, i.e., the structure corresponding to formula (a-4):

[0044]

[0045] The above structure is Three types of structures are prepared and synthesized. Preferably, The resolution can be increased.

[0046] In the above-mentioned first polymer, formula (a-4) is combined with a film-forming resin to make the ((a-4)) structure more evenly distributed in the resist, thereby making the distribution in the resist film more even and better controlling the resolution of the photoresist.

[0047] In the present invention, the second polymer represented by formula (II) consists of the following structure;

[0048]

[0049] The second polymer includes one or more of the structural units shown below, i.e., the structure corresponding to formula (a-5):

[0050]

[0051] The above structure is Three types of structures were prepared.

[0052] The second polymer includes one or more of the structural units shown below, i.e., the structure corresponding to formula (a-6):

[0053]

[0054] The above structure is Three types of structures were prepared.

[0055] In the above-mentioned second polymer, on the basis of combining the structure shown in formula (a-4) with the film-forming resin, the structure shown in formula (a-6) is combined with the film-forming resin, so that its structure can be distributed more evenly in the resist, the acid diffusion is more controlled, and the control of line width roughness (LWR) will be better.

[0056] In an embodiment of the present invention, the first polymer accounts for 60 to 80 wt % of the film-forming resin (A), and the second polymer accounts for 20 to 40 wt % of the film-forming resin (A).

[0057] In an embodiment of the present invention, the photoresist composition further comprises a fluorine-containing resin, and the fluorine-containing resin has a structural unit represented by the following formula (III):

[0058]

[0059] f and g are respectively between 0.01 and 0.99, f+g=1, and f and g respectively represent the molar proportion. f is preferably between 0.2 and 0.8, preferably between 0.3 and 0.7, and more preferably between 0.4 and 0.6. g is preferably between 0.2 and 0.8, preferably between 0.3 and 0.7, and more preferably between 0.4 and 0.6.

[0060] The fluorine-containing resin accounts for 0.01 to 1 wt % in the photoresist composition.

[0061] <Solvent (B)>

[0062] In the present invention, the resist composition of the present invention can be prepared by dissolving the film-forming resin (A) in the following solvent (B). The types of solvent (B) are as follows:

[0063] lactones, such as gamma-butyrolactone;

[0064] Ketones, such as acetone, methyl ethyl ketone, cyclohexanone, methyl n-amyl ketone, methyl isoamyl ketone, and 2-heptanone;

[0065] Alcohols, polyols such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol;

[0066] Compounds having an ester bond, such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, and dipropylene glycol monoacetate.

[0067] Esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate, etc.;

[0068] Ethers such as propylene glycol methyl ether, propylene glycol methyl ether acetate (PGMEA), and propylene glycol methyl ether;

[0069] Aromatic organic solvents such as anisole, ethyl benzyl ether, cresol methyl ether, diphenyl ether, dibenzyl ether, phenethyl ether, butylphenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, and mesitylene.

[0070] These organic solvents may be used alone or as a mixed solvent of two or more.

[0071] In addition, as the solvent (B) component, it is also preferred to select one or two of ether solvents. Preferably, the solvent (B) is one or two of propylene glycol methyl ether acetate and propylene glycol methyl ether, and at this time, as a mixing ratio, the mass ratio of the former to the latter is preferably (40:60) to (70:30).

[0072] The mass ratio of the film-forming resin (A) to the solvent (B) is 100:(1000-30000).

[0073] The second aspect of the present invention provides a pattern forming method, which comprises the following steps: forming a resist film on a substrate using a resist composition, exposing the resist film to high-energy rays, and exposing the exposed resist film using a developer. It includes a developing step and obtains a pattern. More steps can be added as needed.

[0074] For example, the resist composition of the present invention can be used as a substrate (Cr, CrO, CrON, MoSi2, silicon dioxide, etc.) for manufacturing integrated circuits (Si, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, silicon-containing antireflective coatings or organic hydrocarbon coatings) or for mask circuit manufacturing, using spin coating, roller coating, flow coating, dip coating, spray coating, scraping and other suitable coating methods to make the coating thickness 0.01 to 2 μm. It is pre-baked on a hot plate, preferably at 60 to 150° C. for 10 s to 30 min, more preferably at 80 to 120° C. for 30 s to 20 min.

[0075] Then, the resist film is exposed using high-energy rays. Examples of high-energy rays include ultraviolet rays, deep ultraviolet rays, EB, X-rays, excimer lasers, gamma rays, synchrotron radiation, EUV, soft X-rays, etc. When ultraviolet rays, deep ultraviolet rays, X-rays, excimer lasers, gamma rays, synchrotron radiation, EUV, and soft X-rays are used as high-energy rays, a mask is used to form a desired pattern, and the exposure dose is preferably 1 to 200 mJ / cm 2 , more preferably 10 to 100 mJ / cm 2 When EB is used as a high energy beam, the exposure dose is preferably 0.1 to 100 μC / cm 2 , more preferably 0.5 to 50 μC / cm 2 The desired pattern is formed directly or using a mask. The resist composition of the present invention is particularly suitable for fine patterning using high energy KrF excimer laser, ArF excimer laser, EB, EUV, soft X-ray, X-ray, gamma ray, synchrotron radiation, and the like.

[0076] In addition to the usual exposure method, exposure can also be performed by an immersion method in which a liquid such as water having a refractive index of 1.0 or more is sandwiched between the resist film and the projection lens.

[0077] After the exposure, PEB may be performed on a hot plate at preferably 60 to 150° C. for 10 s to 30 min, more preferably 80 to 120° C. for 30 s to 20 min.

[0078] After exposure or PEB, development is performed. For development, for example, 0.1 to 10 wt%, preferably 2 to 5 wt%, of tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide (TPAH) or tetrabutylammonium hydroxide (TBAH) is added, preferably for 3s to 3min, more preferably for 5s to 2min, by dipping, spraying, etc. According to this method of development, the light irradiated part is dissolved in the developer, and the unexposed part is dissolved in the developer, and the expected positive pattern is formed on the substrate.

[0079] Using the resist composition of the present invention, negative development can also be performed by organic solvent development to obtain a negative pattern. The developer used at this time is 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methylcyclohexanone, acetophenone, methylacetophenone, propyl acetate, butylacetic acid, isobutyl acetate, amyl acetate, butyl acetate, isoamyl acetate, propyl formate, butyl formate, isobutyl formate, amyl formate, isoamyl formate, methyl valerate, methyl pentenoate, methyl crotonate, ethyl crotonate, Methyl propionate, ethyl propionate, 3-ethylethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, amyl lactate, isoamyl lactate, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, methyl benzoate, ethyl benzoate, phenyl acetate, benzyl acetate, methyl phenylacetate, benzyl formate, phenylethyl formate, methyl 3-phenylpropionate, benzyl propionate, ethyl phenylacetate, ethyl 2-phenylacetate, etc. These organic solvents can be used alone or in combination of two or more.

[0080] Furthermore, after the development step, it may be rinsed with water, preferably for 3 s to 3 min, more preferably for 5 s to 2 min, by a conventional method such as a dipping method or a spraying method.

[0081] The developed hole pattern and groove pattern can also be shrunk by heat flow, RELACS technology, DSA technology, etc. A shrinking agent is applied on the hole pattern. During the baking process, the shrinking agent is cross-linked on the surface of the photoresist due to the diffusion of the acid catalyst from the photoresist layer, and the shrinking agent is attached to the side wall of the hole pattern. The baking temperature is preferably 70 to 180°C, more preferably 80 to 170°C, and the baking time is 10 to 300s. Finally, the excess shrinking agent is removed to shrink the hole pattern.

[0082] The present invention is further described in detail below in conjunction with embodiments so that those skilled in the art can implement the invention with reference to the description.

[0083] It should be noted that the experimental methods described in the following embodiments are conventional methods unless otherwise specified, and the reagents and materials can be obtained from commercial channels unless otherwise specified.

[0084] <Synthesis example 1>

[0085] The preparation of triphenylsulfide 1,1,2,2-tetrafluoro-4-(methacryloyloxy)butyl-1-sulfonate (G1) comprises the following steps:

[0086] S1. Preparation of 4-hydroxy-1,1,2,2-tetrafluorobutyl-1-sulfonic acid intermediate

[0087]

[0088] Use methanol (about 200mL) to extract 20g of 4-hydroxy-1,1,2,2-tetrafluorobutyl-1-sulfonic acid sodium salt and filter to remove particles, the resulting solution is passed through a column filled with about 8cm AMBERLITETM120H acidic cation exchange resin to obtain a light brown protonated compound solution, and additional methanol is used to rinse away residual sulfonic acid. Volatiles are removed under reduced pressure to obtain a dark brown oil containing black granular spots.

[0089] S2. Preparation of 3,3,4,4-tetrafluorobutyl sultone

[0090]

[0091] The dark brown oil obtained in step S1 is placed in a round-bottom flask connected to a distillation apparatus, and the reaction system is filled with a nitrogen atmosphere. The flask is immersed in a hot wax bath, and the temperature is gradually increased from 130°C to 180°C. The product sultone and water are gradually distilled out and condensed to form a two-phase liquid product. The lower sultone layer is removed using a pipette, dried over anhydrous magnesium sulfate, and filtered to obtain a colorless liquid product.

[0092] S3. Preparation of sodium salt of 2-methyl-2-propenoic acid, 4-sulfo-3,3,4,4-tetrafluorobutyl ester

[0093]

[0094] Methacrylic acid (1.708 g, 19.85 mmol) was slowly added to sodium hydride (1.150 g, 28.66 mmol) in 40 mL of THF. After stirring overnight, the reaction mixture was filtered and the volatiles were removed under reduced pressure. 3,3,4,4-tetrafluorobutyl sultone (3.260 g, 15.66 mmol), methacrylic acid (2.0 mL) and a small amount of hydroquinone were added to the sodium methacrylate solution, and the mixture was then heated at 75 ° C overnight. Acetone (10 mL) was added to the mixture, the solid material was filtered, washed with additional acetone and dried under reduced pressure. The solid material was then extracted with water and filtered. The volatiles were removed under reduced pressure to obtain a white body.

[0095] S4. Preparation of triphenylsulfonate 1,1,2,2-tetrafluoro-4-(methacryloyloxy)butyl-1-sulfonate

[0096]

[0097] 1,1,2,2-tetrafluoro-4-(methacryloyloxy)butyl-1-sulfonic acid sodium salt (2g, 6.02mmol) and triphenylsulfide bromide (2.25g, 6.57mmol) were added to a 100ml round-bottom flask together with 15mL of dichloromethane and 15mL of distilled deionized water, and the mixture was stirred vigorously for 36 hours. Stirring was stopped and the mixture separated into two transparent layers; the organic layer was washed twice with 30mL of 1% (w / w) aqueous ammonium hydroxide solution and 5 times with 30mL of distilled deionized water. The organic layer was dried over sodium sulfate and filtered. Hydroquinone (1mg) was added and the solvent was removed by rotary evaporation and high vacuum to obtain a colorless, viscous oil product (2.65g, 4.76mmol), i.e., triphenylsulfide 1,1,2,2-tetrafluoro-4-(methacryloyloxy)butyl-1-sulfonate.

[0098] Compound G2 was synthesized similarly to the synthesis process of triphenylsulfonyl 1,1,2,2-tetrafluoro-4-(methacryloyloxy)butyl-1-sulfonate (G1);

[0099] use Using commercially available monomers such as , monomers Q1, Q2, Q3, Q4, Q5, and Q6 were synthesized respectively by the methods of step S3 and step S4 in the preparation steps of compound G1.

[0100] Compound G1, compound Q1, compound Q2, and compound Q5 were synthesized by replacing methacrylic acid with the following structure: (CAS No.: 6852-90-0)

[0101]

[0102] The structural formulas of compound G1, compound G2, monomers Q1, Q2, Q3, Q4, Q5, and Q6 are shown in Table 1 below:

[0103] Table 1

[0104]

[0105] <Preparation Example 1>

[0106]

[0107] Prepared from monomers A1, A2, A3, G1 at a molar feed ratio of 35 / 40 / 20 / 5%. A drop feed solution was formed by dissolving A1 (10 g, 42.7 mmol), A2 (11.5 g, 48.8 mmol), A3 (4.1 g, 24.4 mmol), G1 (3.4 g, 6.1 mmol) and 2.1 g of azo initiator 2,2'-azobis(2-methylpropionic acid) dimethyl ester in 90 g of butanone, adding 40 g of butanone to a 3-necked round-bottom flask equipped with a water condenser and a thermometer, and raising the temperature to 65°C. The drop feed solution was supplied to the round-bottom flask using a syringe pump over a period of 4 hours, followed by keeping at 65°C for another 2 hours. The reaction solution was cooled to room temperature, diluted with tetrahydrofuran ("THF") to 25 wt%, and precipitated in a 10-fold (by weight) mixture of heptane and isopropanol (7:3 (w / w)). Copolymer P1 was isolated by filtration and dried under vacuum at 50°C for 24 hours.

[0108] Copolymers P2-P9 were prepared using the same preparation steps as those for preparing copolymer P1. The molar ratios of the raw materials for preparing copolymers P1-P9 are shown in Table 2, where the molar fractions in Table 2 are percentages.

[0109] Table 2

[0110] Copolymer A1 A2 A3 G1 G2 Q1 Q2 Q3 Q4 Q5 Q6 P1 35 40 20 5 0 0 0 0 0 0 0 P2 35 40 20 0 5 0 0 0 0 0 0 P3 35 40 20 0 0 5 0 0 0 0 0 P4 35 40 20 0 0 0 5 0 0 0 0 P5 35 40 20 0 0 0 0 5 0 0 0 P6 35 40 20 0 0 0 0 0 5 0 0 P7 35 40 20 0 0 0 0 0 0 5 0 P8 35 40 20 0 0 0 0 0 0 0 5 P'1 35 40 20 0 0 0 0 0 0 0 0

[0111] <Example 1>

[0112] According to the composition shown in Table 3 below, the copolymer, fluorine-containing resin and solvent were mixed and dissolved, and after dissolution, the mixture was filtered using a filter (pore size 0.2 μm) to prepare a resist composition. The numerical values ​​in Table 3 represent parts by mass.

[0113] Fluorine resin A4

[0114]

[0115] Photoacid generator P

[0116]

[0117] Acid Diffusion Inhibitor Q

[0118]

[0119] The positive resist composition obtained above was uniformly applied on an 8-inch silicon wafer formed with a lower anti-reflection film ("ARC29", manufactured by Nissan Chemical Co., Ltd.) using a spin coater, and pre-baked for 90 seconds at 120°C, and a resist layer with a film thickness of 225nm was formed by drying. Next, an ArF exposure device (wavelength 193nm) NSR-S302A (manufactured by Nikon, NA (numerical aperture) = 0.60, 2 / 3 annular emission) was used to perform selective exposure through a mask. Then, a post-exposure bake (PEB) treatment was performed at 95°C for 60 seconds, and an alkali development treatment was performed at 23°C for 10 seconds using a 2.38% by mass tetramethylammonium hydroxide aqueous solution. Rinse for 30 seconds and spin dry.

[0120] <Evaluation of Pattern LWR>

[0121] In the formed 1:1 L / S pattern, the line width and line length were measured at 50 points in the direction by length measurement SEM "S-9380" (scanning electron microscope, accelerating voltage 300V, manufactured by Hitachi, Ltd.), and three times the standard deviation (s) was calculated from the results as the measured value of LWR, recorded as (3s). The results are shown in Table 3. The smaller the 3s value, the smaller the line width roughness, which means that a more uniform L / S pattern is obtained.

[0122] <Resolution Evaluation>

[0123] In the formation of the above-mentioned resist pattern, the exposure dose (mJ / cm 2 ) and focus to form SL pattern. The maximum resolution of resist is defined as the minimum line width of L / S pattern distinguished and separated under optimal exposure. The image pattern resolution is shown in Table 3.

[0124] Table 3

[0125]

[0126]

[0127] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the embodiments shown and described herein.

Claims

1. A photoresist composition, characterized in that: Comprising a film-forming resin (A) and a solvent (B); the film-forming resin (A) comprises a first polymer and a second polymer, the first polymer having a structural unit represented by the following formula (I), and the second polymer having a structural unit represented by the following formula (II); In formula (I) and formula (II), R is a hydrogen atom, a lower alkyl group or a halogenated lower alkyl group; R1 is a hydrogen atom, a halogen atom, a nitro group, an amino group, an alkyl group having 1 to 3 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, an alkyl group having 1 to 3 carbon atoms containing an ether bond, a keto bond or an ester bond, or an alkenyl group having 2 to 4 carbon atoms containing an ether bond, a keto bond or an ester bond; R2 is a hydrogen atom, a halogen atom, a nitro group, an amino group or an alkyl group having 1 to 3 carbon atoms; L is an alkane group having 1 to 6 carbon atoms containing or not containing an ester bond; M is a sulfonic acid group or a carboxyl group; P is a photoactive cation; n and m are each an integer of 1 to 3; a, b, c, d, and e are each between 0.01 and 0.99, a+b+c+d=1, a+b+c+e=1, and a, b, c, d, and e represent the molar proportions.

2. The photoresist composition according to claim 1, wherein The first polymer accounts for 60 to 80 wt % of the film-forming resin (A), and the second polymer accounts for 20 to 40 wt % of the film-forming resin (A).

3. The photoresist composition according to claim 1, wherein The value of a is between 0.2 and 0.4, the value of b is between 0.3 and 0.5, the value of c is between 0.1 and 0.3, the value of d is between 0.01 and 0.1, and the value of e is between 0.01 and 0.

1.

4. The photoresist composition according to claim 1, wherein Also included is a fluorine-containing resin having a structural unit shown in the following formula (III): f and g are respectively between 0.01 and 0.99, f+g=1, and f and g respectively represent the molar proportions.

5. The photoresist composition according to claim 4, wherein The fluorine-containing resin accounts for 0.01 to 1 wt % in the photoresist composition.

6. The photoresist composition according to claim 1, wherein The first polymer includes one or more of the structural units shown below:

7. The photoresist composition according to claim 1, wherein The second polymer includes one or more of the structural units shown below:

8. The photoresist composition according to claim 1, wherein The second polymer includes one or more of the structural units shown below:

9. The photoresist composition according to claim 1, wherein The mass ratio of the film-forming resin (A) to the solvent (B) is 100:(1000-30000).

10. A pattern forming method, characterized in that: A step of forming a resist film on a substrate using the photoresist composition according to any one of claims 1 to 9, exposing the resist film to high-energy radiation, and developing the resist film to obtain a pattern.

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